The Government’s hopes of securing a consensus on the future of the House of Lords looked in doubt last night as their proposed measures failed to receive cross-party support.

Reform proposals from Leader of the Commons Jack Straw suggested the Lords could be reduced in size by a third and life peerages abolished.

Mr Straw, who had previously set himself against any elected element, also indicated he may contemplate a 50-50 split between elected and appointed members.

But hopes this shift could break the deadlock on the issue seem unfounded after the proposals were criticised for not going far enough. One Tory MP claimed they were a "prescription for constitutional mayhem", while another declared the House should be abolished entirely and replaced with a wholly elected senate.

The Liberal Democrats were more forgiving and said the proposals were a "welcome first stab" at reform but they also urged Mr Straw to go further and make the House predominantly elected. The proposals were set out in a document presented to a cross-party committee seeking consensus on the future of the Upper House, of which Mr Straw is chair.

They also proposed quotas for women and ethnic minorities and that members of the Upper House would be paid a salary and expected to work full-time.

According to reports, the proposals envisage a Lords reduced from 741 members to 450, in which no single party would be able to command an overall majority.

A commission of nine members – a third selected by the party leaders – would make appointments to the chamber, with a duty to reflect the UK’s religious, racial and gender balance.

Conservative Leader in the House of Lords Lord Strathclyde added that "the reform process has a long way to go".

He said: "We are in favour of replacing Labour’s cronyism with an elected House of Lords with more powers which will be better able to hold an over-mighty Government to account."

Liberal Democrat constitutional affairs spokesman Simon Hughes greeted the proposals as a "welcome first stab at a package of reforms which were greatly overdue".

He said: "The talks are also developing a certain amount of common ground and we are moving in the right direction. But Jack Straw has so far failed to grasp the fundamental point: the replacement of the House of Lords must be predominantly elected."

Damien Welfare, co-ordinator of the Campaign for a Democratic Upper House, also urged that the reforms go further. He said: "This sounds like a major step forward but a majority of the members need to be directly elected to achieve a true democratic reform."

Mr Straw aims to produce a White Paper towards the end of the month which would lead to a free vote in both Houses of Parliament before Christmas.

A Government spokesman speaking on his behalf stressed that the document did not represent his final position and was not yet government policy.

He may revise the proposals based on the committee’s response and on discussions with Cabinet colleagues and the Government’s reaction to the upcoming Cunningham Committee report on the conventions governing relations between the two Houses.

The spokesman said: "This document is Jack Straw’s attempt to facilitate cross-party discussion and that discussion is continuing. It is not government policy."

Senior Tory Sir Patrick Cormack said if the leak was correct it indicated Jack Straw had "totally taken leave of his constitutional senses".

 The MP for Staffordshire South said: "These proposals would be a prescription for constitutional mayhem." , setting the two chambers against each other and that would, in effect, not mean the reform but the abolition of the House of Lords.

"Apart from anything else, this would lead to the creation of another class of professional politician which would be inordinately expensive."