Britain's Coalition strains on EU covered in EurActiv
Cameron may see the political benefit of a more assertive approach to Brussels after his decision to veto the new EU treaty won him praise from eurosceptics on the right of his Conservative Party and brought him a boost in the opinion polls.
However, it angered his pro-European junior coalition partners, the Liberal Democrats.
Cameron said it was a "myth" his veto left Britain isolated, saying eurozone members had met without Britain for years. He added that other EU states may eventually reject the pact.
Britain has opened a new battle front with its EU partners by saying members of the new "fiscal compact" should not take decisions on issues affecting the EU's single market for trade.
"Britain's interest is in having a strong single market that's determined at the level of the 27," Cameron said.
He said Britain would be part of agreements it had a national interest in joining, such as the EU single market and NATO, but not of the Schengen passport-free zone or the euro, which it had no national interest in joining.
"We are a lot better off outside the euro, with our own currency and our very low interest rates that we have right now," he said.
Britain's Deputy Prime Minister Nick Clegg, the Liberal Democrat leader, is to host a meeting of his liberal allies from around Europe in London on Monday to promote his agenda of re-engagement with the EU after Cameron's treaty veto.