Tony Blair's desire to keep on side with the United States could scupper efforts to outlaw the death penalty worldwide, according to one of the campaigners against capital punishment.
With Italy seeking support from the United Nations for a worldwide moratorium on execution, British reluctance to back the campaign has infuriated opponents of the death penalty.
Marco Cappato, an Italian MEP and campaigner for a moratorium, told The Independent: "I don't think that Tony Blair is against abolishing the death penalty. But if he doesn't change his diplomatic resistance there is a risk of becoming responsible for the failure of a worldwide moratorium."
Mr Cappato is a colleague of Marco Pannella, the Italian civil rights campaigner who went on hunger strike after hearing that Saddam Hussein was to be executed.
Britain's caution over the issue is, Mr Cappato said, because of "the wish for a good relationship" with Washington. However, he argued that even in the US there are growing doubts about capital punishment.
Mr Pannella's campaign prompted the Italian Prime Minister, Romano Prodi, to put the proposal before the UN's general assembly. But Britain was one of the countries which did not back it.
Diplomats said that while Britain opposes the death penalty, it was sceptical about getting a resolution through the UN.
The last effort to win a UN-sanctioned moratorium failed by a narrow margin. However, Mr Cappato said 45 countries had switched sides since then.
A British official said: "The UK is signed up to the EU's common position on the death penalty and pursues this diplomatically at all levels. Discussions within the EU on how to proceed are still under way."