Labour MPs will push Burnham to back voting reform in first 100 days

Exclusive: Nearly 100 Labour MPs support commission on changing the system used for Westminster election

• Why do some Labour MPs want electoral reform and will it happen?

Andy Burnham will face an immediate test of his backing for electoral reform in his first week in parliament as prime minister, with almost 100 Labour MPs supporting a bid for a new national commission.

Burnham, a longtime advocate of electoral reform, will be asked to support the new commission into ditching first past the post in his first 100 days as prime minister.