British Prime Minister David Cameron’s rejection of a landmark accord to quell Europe’s debt crisis generated cracks in his cabinet Sunday, sparking sharp criticism from the junior partners in his ruling coalition, the Liberal Democrats.

Cameron, a Conservative euro-skeptic, on Friday made Britain the only nation within the ­27-member European Union to reject a summit pact aimed at shoring up the foundations of the currency through a new treaty spelling out, among other things, binding limits on government spending and borrowing.

Cameron’s move brought an extraordinarily scathing reaction from his deputy prime minister, Nick Clegg, who bluntly said Sunday that he was “bitterly disappointed” in Cameron’s decision. He added that the move could now isolate Britain in Europe and threatened to make it a “pygmy in the world.”

“This is bad for Britain,” Clegg said in a lengthy BBC interview Sunday. “Euro-skeptics should be careful what they wish for.” He said that Britain was close to becoming a nation “hovering somewhere in the Mid-Atlantic and not being taken seriously in Europe.”

Clegg’s comments did not appear to put the government in immediate jeopardy, with the deputy prime minister saying Sunday that it would be wrong for the Liberal Democrats to consider withdrawing from the coalition. But his remarks suggested how deeply the debt crisis in Europe has rattled politics in Britain, which has jealously guarded the pound and eschewed the euro.

Britain isolated

Although Britain is not a member of the 17-nation euro zone, it is a member of the larger European Union. Thus, Cameron’s decision to reject the E.U. treaty changes at the summit forced the other 26 nations of the union to try to forge a new international pact among themselves.

Cameron’s veto also complicated the path for those nations, which face potential legal hurdles in drafting a deal that would boost the powers of E.U. institutions without the support or participation of one of its key members, Britain.

Cameron vetoed a broader E.U. deal after German Chancellor Angela Merkel and French President Nicolas Sarkozy rejected a bid by Cameron to win new assurances that future E.U. rules would not hurt London’s financial district.

Cameron was under pressure to take a tough stance by an increasingly powerful bloc of anti-E.U. lawmakers in his Conservative Party, where some are calling for a referendum on whether London should withdraw from the union.

His decision brought swift praise from leading euro-skeptic Conservatives, including his foreign minister, William Hague.

“It is the duty of every Prime Ministerto put the national interest first, even if it means sacrificing quick applause back home or refusing to please his peers in other countries,” Hague wrote in a commentary for London’s Telegraph newspaper. “Not every Prime Minister passes that test but in the small hours of Friday in Brussels, David Cameron again showed that he does.”

Clegg’s comments Sunday were far stronger than his reaction Friday, when he showed more understanding for Cameron’s decision. Soon after Cameron vetoed the deal, Clegg issued a statement calling the prime minister’s conditions for an agreement “modest and reasonable.”

But Clegg was coming under pressure from his Liberal Democrats, who hold a far more pro-European stance, to more aggressively denounce Cameron’s move. Other pro-European Liberal Democrats in Cameron’s cabinet, including Business Secretary Vince Cable, also were denouncing the decision.

But Clegg went out of his way Sunday to calm speculation that Cameron’s veto could bring down the coalition government.

“It would be even more damaging for us as a country if the coalition government were now to fall apart,” Clegg said. “It would be a disaster.”