Labour’s attempts to win a majority in the Commons have come under further attack as the Government vowed to press ahead with plans to cut the number of MPs by 50 to 600.

The move, is expected to hit Labour disproportionately, was confirmed by Ministers today. Oliver Letwin chose to ignore the recommendations of a cross-party committee of MPs – which criticised the Government’s plans as “unsatisfactory”- and claimed there was “no merit” in re-opening the issue.

The Tories want to equalise the number of voters in each constituency, which currently vary from 22,000 to 108,000, and for no constituency to have more than 5 per cent variance compared to the average.

However the reforms could deliver the Tories an extra 20 seats at the 2020 General Election. It is one of several changes, including cuts to Labour funding through the Trade Union Bill, which have been described as attempts to “rig the rules” of politics.

Last year the Tory proposals to cut the number of MPs was heavily criticised by the Commons’ Political and Constitutional Reform Committee, which said the plans “seriously limited the extent to which local ties and existing constituency boundaries were able to be taken into account.”

At the time Jeremy Corbyn said: “David Cameron and the Conservative Party are trying to rig the constitution for their own political ends. They want to reduce by fifty the number of directly elected Members of Parliament under the guise of reducing the cost of politics, whilst cramming the Lords full with their unelected friends and donors at the taxpayer’s expense.”

Now Labour MPs will wait for the report of the Boundary Commission, which is due in 2018.