PARIS — Europeans may be on edge about Wednesday’s summit meeting in Brussels on the euro crisis, but so are their leaders and their tempers.

On Sunday, when the 27 leaders had their first round of deliberations, emotions ran high and some tough exchanges soon leaked out to the news media, designed as ever to make individual leaders look smarter, more intelligent or more courageous than the others.

For all the talk of European solidarity, these summit meetings tend to be covered — and briefed by officials — as boxing matches, with every national delegation trying to show its boss as the champion of national interests against the collective horde.

Prime Minister David Cameron of Britain tried that on Sunday, insisting that there be a full summit meeting of all 27 members of the European Union on Wednesday, as well as a meeting of the 17 nations that use the euro. Facing an internal party revolt, he means to protect Britain’s interests, he said, in case the euro zone countries get ahead of themselves and do damage to the single market that is one of the European Union’s greatest strengths.