David Cameron and Ed Miliband clash over Lords reform
There have been heated exchanges at Prime Minister's Questions following a rebellion by 91 Conservative MPs on House of Lords reform.
Ed Miliband accused David Cameron of "losing the confidence of the country" and control of his party.
The PM rejected the criticism and urged all supportive MPs to back the Lords Reform Bill through the Commons.
Number 10 said the coalition wants to build consensus and ask MPs to vote on the bill's timetable in the autumn.
Despite the rebellion, the government still won the vote on the principle of its proposed reforms to Parliament with a majority of 338.
But a motion to set out a timetable for the Lords Reform Bill had to be dropped by the government in the face of certain defeat because it was opposed by Labour and by Tory rebels.
Mr Miliband said Mr Cameron had "lost control of his party" and the rebellion showed he was "weak".
The prime minister responded: "If we want to see House of Lords reform all of those who support House of Lords reform need to not only vote for House of Lords reform, but support the means to bring that reform about."
Ministers say they now plan to ask MPs to vote on the timetabling of the bill - regarded as crucial if it is to get through Parliament without being talked out by opponents - in the autumn.
A spokesman for the prime minister said: "Clearly there isn't a consensus on the timetable and we are ready to engage with people who support House of Lords reform to find a way forward."
BBC political correspondent Norman Smith said this implied the government would seek to concentrate its efforts on securing a deal with Labour rather than convincing Conservative rebel backbenchers.
However, a Labour source indicated the party may not be willing to negotiate: "It's about the thoroughness of the debate, not the number of days timetabled."
The Labour leader said the government's problems had started "months ago" with the Budget and attacked the coalition's economic record saying it had presided over a double dip recession.
He said: "The biggest failure facing this government is not the programme motion on Lords reform, it's their whole economic plan."
Mr Cameron rejected Mr Miliband's claim, saying unemployment was coming down and blaming Labour for the economic situation.
He said: "We will never forget what we were left by the party opposite... never has so much been borrowed; never has so much been wasted; never has so many people been let down and this country will never forgive them for what they did."
With apparent reference to a run-in the PM had with Lords rebel Jesse Norman on Tuesday, the Labour leader hit back saying: "The redder he gets the less he convinces people."
"There's only one person round here who is red and that's Red Ed, running the Labour party," Mr Cameron countered.
Following the Conservative rebellion on Lords reform, the Liberal Democrats have warned of "consequences" if the Tories fail to back the bill.
Deputy leader of the party Simon Hughes told the BBC that if the Conservatives failed to deliver on this part of the coalition deal, the Lib Dems might not back plans to reform constituency boundaries, "which is advantageous to them".
During Prime Minister's Questions Conservative MP Adam Afriyie called for a review of the coalition agreement to deal with the "new issues" arising.
Mr Cameron stopped short of agreeing with him, but said it was important in coalition to "keep working out the next set of things you want to achieve".
Mr Afriyie later told the BBC's Daily Politics that "a cool, calm look at the coalition agreement would be useful all round" because of "emerging tensions" between the two coalition partners.