DAVID Cameron will face an uncomfortable showdown with his critics in the House of Commons today as he seeks to justify his EU veto, which his deputy Nick Clegg, who will be seated next to him, roundly denounced as "bad for Britain".

The highly critical comments from the Deputy Prime Minister, which came just two days after he gave carefully worded approval to Mr Cameron's actions, revealed the extent of Cabinet divisions over Europe.

The rift threatens to cause major ructions in the Coalition between the Conservatives and Liberal Democrats, despite strong assurances from senior Cabinet members that the partnership would not break up over the disagreements.

In the Commons today, the Prime Minister will be strongly supported by the vociferous ranks of Conservative eurosceptics, one of whom, Mark Pritchard, last night denounced the "self-righteous whingeing" of Liberal Democrats and declared: "Better to be a British bulldog than a Brussels poodle."

Alex Salmond called on Mr Cameron to convene an urgent meeting with the leaders of the devolved administrations, accusing him of "blundering into isolation in Europe", which, the First Minister insisted, had left the Coalition with "zero credibility" in Brussels and, he feared, would harm Scottish interests.

As Liberal Democrat hackles were raised by what some see as the UK being placed on the periphery of Europe, rumours spread that a furious Vince Cable was on the point of resigning over the Prime Minister's dramatic veto at the Belgian summit.

The Business Secretary, who accepted the policy that led to the veto was a "collective decision by the Coalition", nonetheless expressed concern that Britain had ended up "in a bad place" at the EU summit. However, his office swiftly scotched the rumours, describing them as "categorically untrue". A spokesman said: "Vince has no intention of resigning."

Yet the depth of LibDem unhappiness was on full display when Mr Clegg expressed his "bitter disappointment" at the outcome, a departure in stark contrast to the bonhomie evinced in the Downing Street rose garden when the Coalition's formation was announced.

Speaking on BBC's Andrew Marr Show, the Deputy Prime Minister said: "Now, there is a danger the UK will be isolated and marginalised within the European Union. I don't think that's good for jobs in the City or elsewhere, I don't think it's good for growth or for families up and down the country."

Mr Clegg vowed to do everything in his power to make sure the "setback does not become a permanent divide".

Asked what he had said to the Prime Minister when his colleague, in a 4am telephone call on Friday, told him of the veto, the europhile Liberal Democrat leader replied: "I said this was bad for Britain. I made it clear that it was untenable for me to welcome it."

The Deputy Prime Minister – who conspicuously avoided criticising Mr Cameron personally – argued that, "of course things would have been different", if he had been at the summit, saying he was not under the same constraints from his MPs as the Tory leader was.

However, Mr Clegg let fly at

those Conservatives who hailed the veto, saying they were "spectacularly misguided".

"There's nothing bulldog about Britain hovering somewhere in the mid-Atlantic, not standing tall in Europe, not being taken seriously in Washington," he said.

Ed Miliband said: "The Deputy Prime Minister has confirmed what we have been saying: this is a bad deal for Britain; it secures no extra protection for British business." The Labour leader added: "The Prime Minister made this deal not on national interests but because of the Conservative Party."

Elsewhere, former LibDem leader Lord Ashdown branded the veto a "catastrophically bad move", but insisted the Coalition had to survive to help navigate the country through the current economic crisis.