Berlusconi is a very dubious friend to have

Tom Arbuthnott Foreign Policy Centre

Mr Blair has also found common cause with Spanish leader Jose Maria Aznar, another right-winger.

Labour leaders fear the "unholy trinity" will stand in the way of moves towards establishing workers' rights on an EU-wide basis.

But after coming to power in 1997, Tony Blair was seen as the key figure in a Europe establishing a centre-left consensus.

He quickly established friendships with French Prime Minister Lionel Jospin and later, German Chancellor Gerhard Schroeder.

Similarities of approach

Tom Arbuthnott, head of the Europe programme at independent think tank, the Foreign Policy Centre, said Mr Blair had "similarities of approach rather than ideology" with his counterparts in Italy and Spain.

Mr Berlusconi's Forza Italia established "can do politics" outside the traditional framework of Italian politics.

Silvio Berlusconi frightens British trade unions

Mr Arbuthnott told BBC News Online: "[Berlusconi] was saying politics is rubbish - he wasn't being held hostage to the old left and old right.

"Blair was divorcing the Labour Party from parts of its past. They both have enormous similarities of approach.

"Part of the approach is based on entrepreneurial ideas of freeing up Europe.

"Blair is focused on delivery - setting up targets and delivering them."

Mr Arbuthnott said the Lisbon summit, which forms the basis for talks in Barcelona, was largely the project of Mr Blair and Mr Aznar.

Rights are wrong?

"The French approach is to have more control - social legislation at European level.

"The British, Spanish and Italians don't like it.

"The British difference isn't that labour rights are wrong, it is that they shouldn't necessarily be dealt with at European level."

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But this temporary alliance is unlikely to harm other friendships Mr Blair cultivates, such as those with Mr Jospin and Mr Schroeder.

"Blair and Schroeder have a fair amount in common on other issues - they have signed joint declarations. There are strong links between the Labour Party and the SPD."

"With Denmark and the Netherlands, there is a friendship group pushing through the issue of Common Agricultural Policy reform.

"There is an enormous society of the left."

And Mr Blair is likely to remain careful his numerous friendships and temporary alliances do not bind him too closely to the European right.

Mr Arbuthnott added: "Berlusconi is a very dubious friend to have - his colleague in government Gianfranco Fini's party's past is in the fascist movement."