Jack Straw has appealed for compromise over House of Lords reform and said MPs could vote on the issue within the next couple of months.

The Commons leader confirmed that he backed the introduction of a partially-elected second chamber where no single party held an overall majority.

In a speech in London, he said the best chance of avoiding the deadlock that blighted previous reform attempts was to propose the phased introduction of "a balanced, hybrid house".

Proposals floated by Straw - and leaked to the Sunday Times at the weekend - include cutting the number of members by a third, with half elected and half appointed by an independent panel.

They failed to win cross-party support but Straw used his speech to urge MPs and peers to find common ground and avoid scuppering another chance of reform.

The most recent attempt to remove the remaining hereditary peers foundered when the Commons failed to agree on which of several options to back.

Straw, addressing the constitution unit at University College London, said: "There are of course many issues to be resolved over the next few weeks and months.

"But broadly speaking, my best guess is that a consensus is most likely to be found in a balanced, hybrid house, with the change phased in over several parliaments.

"The issue of how members are recruited to the second chamber is an area, one among many, where progress will require compromise.

"There are a myriad of opinions on how a reformed lords should look.

"Deadlock again will be very easy to achieve. On the other hand, progress will be hard fought, but it will be worth the effort.

"My appeal to those involved in the debate is not to make the best the enemy of the good, not to put their idea of perfection in the way of progress."

He conceded that there remained "strong opposition in some quarters" to having any elected element - a position he himself previously took but now rejects.

But he insisted the second chamber could not be allowed to become a "rival" to or replicate the Commons.

Measures would also be required to ensure it was representative of women, ethnic minorities and the regions and contained experienced voices from outside politics, he said.

On the timing of a vote, he said: "In terms of the future timetable for reform, I hope to meet the government's manifesto commitment on a free vote on composition of a reformed second chamber around the turn of the year."

Straw said Labour's initial reforms of the Lords had led to a "seismic change" in the way it worked.

"But now, to complete the job, we must take one further significant stride," he added.

The proposals that emerged at the weekend were set out in a document presented to a cross-party committee seeking consensus on the future of the upper house, of which Straw is chairman.

They proposed quotas for women and ethnic minorities and suggested members of the upper house would be paid a salary and expected to work full-time.

According to the leak, 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.