LONDON – Prime Minister David Cameron fiercely defended his decision to block a landmark pact by all 27 members of the European Union on Monday as he was accused by opposition politicians of stripping Britain of its influence in Europe.

Last Friday, Cameron refused to sign a new pact in Brussels aimed at stemming the two-year debt crisis engulfing euro-zone nations. Of the 27 countries in the European Union (E.U.), Britain was the only one to bluntly block a pact aimed at introducing caps and penalties on governments’ spending and borrowing. The 26 other countries have agreed to join or consider joining a "new fiscal compact," without Britain’s involvement.

Cameron told Parliament on Monday that he “genuinely looked to reach an agreement,” but was forced to wield Britain’s veto after he was unable to secure concessions he said were needed to protect Britain’s financial sector from oppressive E.U. regulation. He insisted that Britain’s demands were “modest, reasonable, and relevant.”

“The choice was a treaty without proper safeguards, or no treaty. And the right answer was no treaty,” said an unapologetic Cameron. “It was not an easy thing to do, but it was the right thing to do.”

Initial polling shows that Cameron has wide public support for his move. In a Times/Populus poll published Monday, 57 percent of people agreed that Cameron was right to veto the agreement, while only 14 percent opposed his decision. More than half – 56 percent – thought the result would be diminished British influence in the E.U., but 44 percent thought it would protect London’s financial district, compared to 12 percent who did not.

Deputy Prime Minister Nick Clegg was noticeably absent from the House of Commons debate, which comes a day after he ratcheted up fears the coalition government was under serious strain when he told the BBC he was “bitterly disappointed with the outcome.” Clegg, who is the leader of the pro-European Liberal Democrat party, the coalition’s junior partners, told the BBC: “There is nothing bulldog about Britain hovering somewhere in the mid-Atlantic, not standing tall in Europe, not being taken seriously in Washington.”

The European Union is the world’s largest single market, and Cameron repeatedly stressed that Britain is still a full-fledged member that will continue to be prominent player on various issues from foreign policy to climate change. But he said: “I believe in an E.U. with the flexibility of a network, not the rigidity of a bloc.”

Underscoring what a divisive issue Europe is in Britain, Monday’s debate was raucous even by the normal rough-and-tumble standards of the House of Commons. During one of his many interventions, the speaker of the House told a lawmaker who was shouting that he was worried about his health: “He must calm himself, have a lie down if necessary.”

It remained unclear whether Britain would allow the other 26 E.U. nations in the "new fiscal compact" to use the larger bloc’s institutions, including, for instance, the European Court of Justice, which could help to enforce new measures.

Cameron told Parliament the government would be investigating the issue further. "This is new territory and it does raise important issues," he said.

Opposition Labor Party leader Ed Miliband lashed out at Cameron, accusing him of bending to the wishes of his party’s anti-European right wing and casting Britain adrift as the other European nations begin a new era of negotiating without Britain at the table.

The outcome was a "diplomatic disaster of 26 going ahead and one country – Britain -- being left behind," he said.