Labour MPs have rejected Gordon Brown’s plans to reform MPs expenses.

The proposals were launched by the Prime Minister on YouTube last week, with the Government planning to hold a vote as soon as Thursday. But West Midlands-based backbenchers in Mr Brown’s party said they were concerned that the changes had been announced before an independent inquiry had finished its work.

Some also criticised the Government’s plan to scrap the controversial second homes allowance and replace it with an attendance allowance, which would pay MPs a flat rate for each day they attended Parliament.

MPs living outside central London currently claim up to £23,083 for accommodation costs. Mr Brown wants to replace this with a daily allowance for turning up at Westminster, following controversies including the row over expenses claimed by Jacqui Smith, the Home Secretary and MP for Redditch,.

Some backbenchers are angry that they are being asked to vote while Sir Christopher Kelly, chairman of the Committee for Standards in Public Life, is still carrying out his inquiry.

Mr Brown’s position has been further weakened by public criticism from Sir Christopher, who said the public would not accept MPs deciding their own expenses. With both the Conservatives and Liberal Democrats opposing the scheme, the Prime Minister could be forced into a climbdown to avoid defeat in Thursday’s vote. Richard Burden (Lab, Northfield) said: “I am uncomfortable with what is being proposed. Sir Christopher is taking a look at this issue and I think the public wants to see an outside view, rather than politicians doing it themselves.”

Mr Brown should be able to count on the support of Government Ministers, who include Birmingham MPs Liam Byrne (Lab, Hodge Hill) and Sion Simon (Lab, Erdington). Meanwhile, rival proposals put forward by Conservatives would lead to massive cuts in expenses claimed by married couples in Parliament – including Julie Kirkbride (Con, Bromsgrove) and her husband Andrew Mackay (Con, Bracknell).

They both take advantage of the second-home allowance, with Mr Mackay claiming £22,575 last year while Ms Kirkbride claimed the maximum of £23,083. Conservative leader David Cameron wants to ban MPs who cohabit from claiming the allowance more than once.