diff --git a/substrate/Cargo.lock b/substrate/Cargo.lock
index 3c944740b7..6269e03360 100644
--- a/substrate/Cargo.lock
+++ b/substrate/Cargo.lock
@@ -7561,6 +7561,7 @@ dependencies = [
  "parity-scale-codec",
  "rand 0.7.3",
  "serde",
+ "sp-arithmetic",
  "sp-phragmen",
  "sp-phragmen-compact",
  "sp-runtime",
diff --git a/substrate/primitives/core/src/testing.rs b/substrate/primitives/core/src/testing.rs
index b5e6f4c7af..9e83090bcf 100644
--- a/substrate/primitives/core/src/testing.rs
+++ b/substrate/primitives/core/src/testing.rs
@@ -16,10 +16,10 @@
 
 //! Types that should only be used for testing!
 
-use crate::crypto::{KeyTypeId, CryptoTypePublicPair};
+use crate::crypto::KeyTypeId;
 #[cfg(feature = "std")]
 use crate::{
-	crypto::{Pair, Public},
+	crypto::{Pair, Public, CryptoTypePublicPair},
 	ed25519, sr25519,
 	traits::BareCryptoStoreError
 };
diff --git a/substrate/primitives/phragmen/Cargo.toml b/substrate/primitives/phragmen/Cargo.toml
index ff3b331406..29fc0ed41e 100644
--- a/substrate/primitives/phragmen/Cargo.toml
+++ b/substrate/primitives/phragmen/Cargo.toml
@@ -15,13 +15,14 @@ targets = ["x86_64-unknown-linux-gnu"]
 codec = { package = "parity-scale-codec", version = "1.0.0", default-features = false, features = ["derive"] }
 serde = { version = "1.0.101", optional = true, features = ["derive"] }
 sp-std = { version = "2.0.0-dev", default-features = false, path = "../std" }
-sp-runtime = { version = "2.0.0-dev", default-features = false, path = "../../primitives/runtime" }
 sp-phragmen-compact = { version = "2.0.0-dev", path = "./compact" }
+sp-arithmetic = { version = "2.0.0-dev", default-features = false, path = "../arithmetic" }
 
 [dev-dependencies]
 substrate-test-utils = { version = "2.0.0-dev", path = "../../test-utils" }
 rand = "0.7.3"
 sp-phragmen = { version = "2.0.0-dev", path = "." }
+sp-runtime = { version = "2.0.0-dev", path = "../../primitives/runtime" }
 
 [features]
 default = ["std"]
@@ -30,5 +31,5 @@ std = [
 	"codec/std",
 	"serde",
 	"sp-std/std",
-	"sp-runtime/std",
+	"sp-arithmetic/std",
 ]
diff --git a/substrate/primitives/phragmen/compact/src/assignment.rs b/substrate/primitives/phragmen/compact/src/assignment.rs
index 587e482ccb..4630a494fc 100644
--- a/substrate/primitives/phragmen/compact/src/assignment.rs
+++ b/substrate/primitives/phragmen/compact/src/assignment.rs
@@ -91,7 +91,7 @@ fn into_impl(count: usize) -> TokenStream2 {
 				}
 
 				// defensive only. Since Percent doesn't have `Sub`.
-				let p2 = _phragmen::sp_runtime::traits::Saturating::saturating_sub(
+				let p2 = _phragmen::sp_arithmetic::traits::Saturating::saturating_sub(
 					Accuracy::one(),
 					p1,
 				);
@@ -115,7 +115,7 @@ fn into_impl(count: usize) -> TokenStream2 {
 				let mut inners_parsed = inners
 					.iter()
 					.map(|(ref t_idx, p)| {
-						sum = _phragmen::sp_runtime::traits::Saturating::saturating_add(sum, *p);
+						sum = _phragmen::sp_arithmetic::traits::Saturating::saturating_add(sum, *p);
 						let target = target_at(*t_idx).ok_or(_phragmen::Error::CompactInvalidIndex)?;
 						Ok((target, *p))
 					})
@@ -126,7 +126,7 @@ fn into_impl(count: usize) -> TokenStream2 {
 				}
 
 				// defensive only. Since Percent doesn't have `Sub`.
-				let p_last = _phragmen::sp_runtime::traits::Saturating::saturating_sub(
+				let p_last = _phragmen::sp_arithmetic::traits::Saturating::saturating_sub(
 					Accuracy::one(),
 					sum,
 				);
@@ -163,7 +163,7 @@ pub(crate) fn assignment(
 			#voter_type: _phragmen::codec::Codec + Default + Copy,
 			#target_type: _phragmen::codec::Codec + Default + Copy,
 			Accuracy:
-				_phragmen::codec::Codec + Default + Clone + _phragmen::sp_runtime::PerThing +
+				_phragmen::codec::Codec + Default + Clone + _phragmen::sp_arithmetic::PerThing +
 				PartialOrd,
 		>
 		#ident<#voter_type, #target_type, Accuracy>
diff --git a/substrate/primitives/phragmen/compact/src/lib.rs b/substrate/primitives/phragmen/compact/src/lib.rs
index 114aeaeb32..9406f944c3 100644
--- a/substrate/primitives/phragmen/compact/src/lib.rs
+++ b/substrate/primitives/phragmen/compact/src/lib.rs
@@ -164,7 +164,7 @@ fn struct_def(
 			PartialEq,
 			Eq,
 			Clone,
-			_phragmen::sp_runtime::RuntimeDebug,
+			Debug,
 			_phragmen::codec::Encode,
 			_phragmen::codec::Decode,
 		)]
diff --git a/substrate/primitives/phragmen/src/helpers.rs b/substrate/primitives/phragmen/src/helpers.rs
index 216de9243e..6b1497e3ad 100644
--- a/substrate/primitives/phragmen/src/helpers.rs
+++ b/substrate/primitives/phragmen/src/helpers.rs
@@ -17,7 +17,7 @@
 //! Helper methods for phragmen.
 
 use crate::{Assignment, ExtendedBalance, VoteWeight, IdentifierT, StakedAssignment, WithApprovalOf};
-use sp_runtime::PerThing;
+use sp_arithmetic::PerThing;
 use sp_std::prelude::*;
 
 /// Converts a vector of ratio assignments into ones with absolute budget value.
@@ -57,7 +57,7 @@ pub fn to_without_backing<A: IdentifierT>(winners: Vec<WithApprovalOf<A>>) -> Ve
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use sp_runtime::Perbill;
+	use sp_arithmetic::Perbill;
 
 	#[test]
 	fn into_staked_works() {
diff --git a/substrate/primitives/phragmen/src/lib.rs b/substrate/primitives/phragmen/src/lib.rs
index f45732d5b8..cf972eb1ed 100644
--- a/substrate/primitives/phragmen/src/lib.rs
+++ b/substrate/primitives/phragmen/src/lib.rs
@@ -34,8 +34,11 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 
 use sp_std::{prelude::*, collections::btree_map::BTreeMap, fmt::Debug, cmp::Ordering, convert::TryFrom};
-use sp_runtime::{helpers_128bit::multiply_by_rational, PerThing, Rational128, RuntimeDebug, SaturatedConversion};
-use sp_runtime::traits::{Zero, Member, Saturating, Bounded};
+use sp_arithmetic::{
+	PerThing, Rational128,
+	helpers_128bit::multiply_by_rational,
+	traits::{Zero, Saturating, Bounded, SaturatedConversion},
+};
 
 #[cfg(test)]
 mod mock;
@@ -60,7 +63,7 @@ pub use helpers::*;
 #[doc(hidden)]
 pub use codec;
 #[doc(hidden)]
-pub use sp_runtime;
+pub use sp_arithmetic;
 
 // re-export the compact solution type.
 pub use sp_phragmen_compact::generate_compact_solution_type;
@@ -107,7 +110,7 @@ pub type WithApprovalOf<A> = (A, ExtendedBalance);
 const DEN: u128 = u128::max_value();
 
 /// A candidate entity for phragmen election.
-#[derive(Clone, Default, RuntimeDebug)]
+#[derive(Clone, Default, Debug)]
 struct Candidate<AccountId> {
 	/// Identifier.
 	who: AccountId,
@@ -120,7 +123,7 @@ struct Candidate<AccountId> {
 }
 
 /// A voter entity.
-#[derive(Clone, Default, RuntimeDebug)]
+#[derive(Clone, Default, Debug)]
 struct Voter<AccountId> {
 	/// Identifier.
 	who: AccountId,
@@ -133,7 +136,7 @@ struct Voter<AccountId> {
 }
 
 /// A candidate being backed by a voter.
-#[derive(Clone, Default, RuntimeDebug)]
+#[derive(Clone, Default, Debug)]
 struct Edge<AccountId> {
 	/// Identifier.
 	who: AccountId,
@@ -144,7 +147,7 @@ struct Edge<AccountId> {
 }
 
 /// Final result of the phragmen election.
-#[derive(RuntimeDebug)]
+#[derive(Debug)]
 pub struct PhragmenResult<AccountId, T: PerThing> {
 	/// Just winners zipped with their approval stake. Note that the approval stake is merely the
 	/// sub of their received stake and could be used for very basic sorting and approval voting.
@@ -155,7 +158,7 @@ pub struct PhragmenResult<AccountId, T: PerThing> {
 }
 
 /// A voter's stake assignment among a set of targets, represented as ratios.
-#[derive(RuntimeDebug, Clone, Default)]
+#[derive(Debug, Clone, Default)]
 #[cfg_attr(feature = "std", derive(PartialEq, Eq, Encode, Decode))]
 pub struct Assignment<AccountId, T: PerThing> {
 	/// Voter's identifier.
@@ -223,7 +226,7 @@ where
 
 /// A voter's stake assignment among a set of targets, represented as absolute values in the scale
 /// of [`ExtendedBalance`].
-#[derive(RuntimeDebug, Clone, Default)]
+#[derive(Debug, Clone, Default)]
 #[cfg_attr(feature = "std", derive(PartialEq, Eq, Encode, Decode))]
 pub struct StakedAssignment<AccountId> {
 	/// Voter's identifier
@@ -301,7 +304,7 @@ impl<AccountId> StakedAssignment<AccountId> {
 ///
 /// This, at the current version, resembles the `Exposure` defined in the Staking pallet, yet
 /// they do not necessarily have to be the same.
-#[derive(Default, RuntimeDebug)]
+#[derive(Default, Debug)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize, Eq, PartialEq))]
 pub struct Support<AccountId> {
 	/// Total support.
@@ -334,7 +337,7 @@ pub fn elect<AccountId, R>(
 	initial_candidates: Vec<AccountId>,
 	initial_voters: Vec<(AccountId, VoteWeight, Vec<AccountId>)>,
 ) -> Option<PhragmenResult<AccountId, R>> where
-	AccountId: Default + Ord + Member,
+	AccountId: Default + Ord + Clone,
 	R: PerThing,
 {
 	// return structures
@@ -561,7 +564,7 @@ pub fn build_support_map<AccountId>(
 	winners: &[AccountId],
 	assignments: &[StakedAssignment<AccountId>],
 ) -> (SupportMap<AccountId>, u32) where
-	AccountId: Default + Ord + Member,
+	AccountId: Default + Ord + Clone,
 {
 	let mut errors = 0;
 	// Initialize the support of each candidate.
diff --git a/substrate/primitives/phragmen/src/mock.rs b/substrate/primitives/phragmen/src/mock.rs
index 5aab5ff2f7..cf9c90334b 100644
--- a/substrate/primitives/phragmen/src/mock.rs
+++ b/substrate/primitives/phragmen/src/mock.rs
@@ -19,11 +19,9 @@
 #![cfg(test)]
 
 use crate::{elect, PhragmenResult, Assignment, VoteWeight, ExtendedBalance};
-use sp_runtime::{
-	assert_eq_error_rate, PerThing,
-	traits::{Member, SaturatedConversion, Zero, One}
-};
+use sp_arithmetic::{PerThing, traits::{SaturatedConversion, Zero, One}};
 use sp_std::collections::btree_map::BTreeMap;
+use sp_runtime::assert_eq_error_rate;
 
 #[derive(Default, Debug)]
 pub(crate) struct _Candidate<A> {
@@ -77,7 +75,7 @@ pub(crate) fn elect_float<A, FS>(
 	initial_voters: Vec<(A, Vec<A>)>,
 	stake_of: FS,
 ) -> Option<_PhragmenResult<A>> where
-	A: Default + Ord + Member + Copy,
+	A: Default + Ord + Copy,
 	for<'r> FS: Fn(&'r A) -> VoteWeight,
 {
 	let mut elected_candidates: Vec<(A, ExtendedBalance)>;
diff --git a/substrate/primitives/phragmen/src/node.rs b/substrate/primitives/phragmen/src/node.rs
index 92ef325a34..432c537052 100644
--- a/substrate/primitives/phragmen/src/node.rs
+++ b/substrate/primitives/phragmen/src/node.rs
@@ -16,11 +16,10 @@
 
 //! (very) Basic implementation of a graph node used in the reduce algorithm.
 
-use sp_runtime::RuntimeDebug;
 use sp_std::{cell::RefCell, fmt, prelude::*, rc::Rc};
 
 /// The role that a node can accept.
-#[derive(PartialEq, Eq, Ord, PartialOrd, Clone, RuntimeDebug)]
+#[derive(PartialEq, Eq, Ord, PartialOrd, Clone, Debug)]
 pub(crate) enum NodeRole {
 	/// A voter. This is synonym to a nominator in a staking context.
 	Voter,
diff --git a/substrate/primitives/phragmen/src/reduce.rs b/substrate/primitives/phragmen/src/reduce.rs
index 1f6f6c3b99..ac4441ddc0 100644
--- a/substrate/primitives/phragmen/src/reduce.rs
+++ b/substrate/primitives/phragmen/src/reduce.rs
@@ -48,7 +48,7 @@
 
 use crate::node::{Node, NodeId, NodeRef, NodeRole};
 use crate::{ExtendedBalance, IdentifierT, StakedAssignment};
-use sp_runtime::traits::{Bounded, Zero};
+use sp_arithmetic::traits::{Bounded, Zero};
 use sp_std::{
 	collections::btree_map::{BTreeMap, Entry::*},
 	prelude::*,
diff --git a/substrate/primitives/phragmen/src/tests.rs b/substrate/primitives/phragmen/src/tests.rs
index 9d16d67495..720a0a3f75 100644
--- a/substrate/primitives/phragmen/src/tests.rs
+++ b/substrate/primitives/phragmen/src/tests.rs
@@ -24,7 +24,7 @@ use crate::{
 	Support, StakedAssignment, Assignment, PhragmenResult, ExtendedBalance,
 };
 use substrate_test_utils::assert_eq_uvec;
-use sp_runtime::{Perbill, Permill, Percent, PerU16};
+use sp_arithmetic::{Perbill, Permill, Percent, PerU16};
 
 #[test]
 fn float_phragmen_poc_works() {
@@ -648,7 +648,7 @@ mod compact {
 	// these need to come from the same dev-dependency `sp-phragmen`, not from the crate.
 	use sp_phragmen::{Assignment, StakedAssignment, Error as PhragmenError, ExtendedBalance};
 	use sp_std::{convert::{TryInto, TryFrom}, fmt::Debug};
-	use sp_runtime::Percent;
+	use sp_arithmetic::Percent;
 
 	type Accuracy = Percent;