David Cameron has issued an appeal to warring Tories and Liberal Democrats to unite behind the coalition not descend into “division and navel-gazing”.
Following last week's Conservative revolt over Nick Clegg's plans for House of Lords reform, the Prime Minister frankly acknowledged there were "profound areas of disagreement" between the two parties.
But in a letter to The Sunday Times, he said it was essential that these differences did not stop them working together in government in the national interest.
"These differences matter and at the next election they will help define us. But we're not in an election, now. We're not even close," he said.
"People see riots and financial instability across Europe on the television news. They will tolerate tough choices if they see that you stand up for the right things together.
"But they will not tolerate division and navel-gazing. They know that the problems are big and they do not want to see politicians fall out in the process of dealing with them.
"That is why we must rise to the challenge, recognise the extraordinary and challenging nature of the times we live in - and serve the national interest by delivering a strong, decisive and united government."
Mr Cameron did offer an olive branch to Conservatives who feel that he has given too much ground to the Lib Dems - spelling out some of the areas where they will campaign on different policies at the next election.
"On Europe, for instance, we British need a fresh settlement - and a fresh mandate. Work on that can begin now but it is an issue to deal with in the next parliament, under a majority Conservative government," he said.
"I take a profoundly different view from most Liberal Democrats on the European Convention on Human Rights, too. I want to do whatever it takes to keep our country safe, restoring the ability to deport dangerous criminals and terrorists even if it means radical action in this area.
"And as I set out in a speech on welfare the other day, the next Conservative government must do more to end the benefits culture."
Energy Secretary Ed Davey said the Tories and Liberal Democrats were parties with different values and histories.
But he defended the coalition in the wake of this week's Conservative rebellion on Lords reform - and insisted the plans were not dead.
He told the Sky News Murnaghan programme: "People are forgetting that we had a historic vote in the Commons just recently when a huge majority voted in favour of the principle of a democratically elected House of Lords.
"That has not happened before.
"I also believe it is part of the Coalition Agreement and the Conservative Party will want to honour their agreement and I'm delighted the Prime Minister said he's going to have another go."
Mr Davey attacked the "political games" played by Labour and said the coalition still had work to do to clear up the financial problems left by the last government.
Labour's deputy leader Harriet Harman told the Sky News Murnaghan programme the Government had dropped the ball on Olympic security, insisting ministers were responsible for the problems.
She said: "We all want the Olympics to be the massive success I'm sure they are going to be but security is the Government's responsibility.
"They should have had day-to-day vigilance on this and the irony in calling on troops to come back and help them at a time when so many of them are being made redundant.
"I think they have been dangerously incompetent on this and I hope they are going to get themselves sorted out before the Games and really there is going to have to be a major post-mortem after.
"The problem is they lost their focus - the Government is such a shambles, they are not doing the basic things the Government should be doing - the basic things are security and the economy.
"You can't just give people a tonne of public money and say 'now it's your responsibility'.
"Security is the Government's responsibility and if they contract it out, they can't just wash their hands of it."
Ms Harman backed giving bonuses to troops called up to cover the missing security guards.
She noted other public sector workers are being offered £500 for working during the Games but refused to name a figure for what she thought would be appropriate for soldiers.
And Ms Harman added: "That bonus should come from G4S. They took on the contract - certainly it was the responsibility of the Government to supervise the contract and they have shown themselves lacking in doing that - but it shouldn't be the taxpayer that should be paying for the bonus which I'm sure everyone thinks they should get."
Lib Dem former leader Sir Menzies Campbell warned Lib Dem MPs would not support Tory plans to redraw the parliamentary boundaries - thought to be worth up to 20 seats to the Conservatives at the next election - if Lords reform was abandoned.
"If you are a Liberal Democrat MP whose seat has been pretty substantially carved up as a result of the proposals for a review of the boundaries, then the idea that you would simply march into the lobby in support of the Conservative Government's particular anxiety to obtain this piece of legislation is one that may be very hard to swallow," he told BBC1's The Andrew Marr Show.
"I don't believe that it can be expected that we will simply form up in the way that some people will think."
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