Tony Blair's relationship with his Italian opposite number Silvio Berlusconi has so many intriguing facets that the veteran Italian anarchist and satirical playwright, Dario Fo - who detests them both - has threatened to write a play about it.
The two politicians are of a like mind on Iraq, Iran, George Bush, the EU, trade union law, and on whether Sardinia is a nice place to spend the summer. Mr Blair's opening words at a press conference to mark the Italian leader's visit to London two years ago were: "I really do not think the relationship between Britain and Italy has ever been stronger." It would, indeed, be difficult to point to a closer bond between a British and Italian leader since Gladstone's day. The downside of this London-Rome axis is that it is almost calculated to enrage the Labour Party. Silvio Berlusconi is up there with Rupert Murdoch and George Bush on the shortlist of friends of Tony Blair that Labour activists loathe most.
Mr Berlusconi's arrival was a lucky break for Mr Blair, who was engaged in a battle with the French and Germans over EU labour laws. Previously, his only ally was the lightweight figure of Spain's Jose Maria Aznar. In February 2002, Mr Blair went on a pilgrimage to Rome to cement the new Blair/Berlusconi pact. From it came eight papers on how to make the EU more business-friendly, which the two leaders presented to the EU summit in Barcelona.
This was a last straw for John Monks, the much-respected general secretary of the TUC, who ended years of loyalty to Labour leaders by proclaiming that Mr Blair's friendship with Berlusconi was "bloody stupid". But the Blair-Berlusconi pact continued to be a consistent counterweight to the now-frayed Franco-German axis, even if the Italian Prime Minister went cold when proposed changes to the Common Agricultural Policy threatened to hurt Italian producers.
More importantly, the two leaders have been united on world affairs, particularly in their support for George Bush. When Mr Blair set out, two months after 11 September 2001, to generate Arab support for a "war on terror", he stopped over in Genoa to issue a joint statement with Mr Berlusconi on the importance of overthrowing the Taliban.
Sixteen months later, as war loomed in Iraq, they emerged as co-leaders of what they liked to think of as New Europe, lining up in support of the Iraq war.
But what may have annoyed Labour activists more than anything is not the political affinity between Blair and Berlusconi but the Prime Minister's love of Italian hospitality. In 2004, the Blair family spent part of their summer holiday in Mr Berlusconi's 27-bedroom Sardinian villa. And last year the Italian newspaper, Corriere della Sera, ran a graphic account of the trappings of wealth that the Blairs have been gifted by Mr Berlusconi, cruelly nicknaming the Blairs the "Sultans of Bling".