As Nicolas Sarkozy said, it is a golden rule in Brussels that an early frontrunner rarely makes it to the finish line. And during this week's European summit, it became clear that Tony Blair's race to become EU president had well and truly run aground.

The French and Germans came close on?Friday to sounding the death knell for the Blair project after a heavy-handed campaign that was insensitive to European sensitivities and ignored the need to secure the early backing of Europe's two key capitals.

EU insiders had warned that the stony silence kept by the German Chancellor Angela Merkel was not a good omen. "There are so many things the British did wrong, but the main thing was that they kickstarted the Blair campaign without getting Merkel on board first. Without her, it was always going to be a losing battle," said one Brussels diplomat.

By so unsubtly pumping up Tony Blair's availability to become Europe's first president – and suggesting he was the obvious candidate for the post – ministers from Gordon Brown downwards blundered spectacularly.

British diplomats, who now have more than 30 years' experience of the labyrinthine world of EU power-politics, should have urged a softly-softly approach on their political masters.

A potential Blair candidacy has been mooted since the Lisbon Treaty, which created the post of President of the Council, was hammered out by the EU's leaders two years ago. But the Blair bandwagon began rolling in earnest as the treaty neared ratification over the summer, when the former prime minister confirmed to Brown that he was interested in the post, depending on the details of the job specification. Blair delegated his former chief-of-staff, Jonathan Powell, to test the diplomatic temperature and gave friends licence to indicate that he could be in the running.

The British PM?was reported to have placed his Europe adviser, John Cunliffe, and the UK's EU ambassador, Kim Darroch, on stand-by to take soundings on a Blair presidency. As this week's Brussels summit of European leaders approached, Britain began to indulge in the sort of megaphone diplomacy so disliked in the EU's corridors. The Foreign Secretary David Miliband embarked on a round of interviews trumpeting the former prime minister's credentials for the job. His suggestion that Blair was the sort of candidate whose motorcade would "stop the traffic" when he rolled into town caused particular irritation among EU leaders with a more modest vision of what the post entailed.

Brown spoke out on behalf of his predecessor at Prime Minister's Question Time on Wednesday and the next day jumped in with both feet at a meeting of European Socialist leaders, whom he lectured on the need to appoint Blair to the presidency. He told them: "This is a unique opportunity to get a strong, progressive politician to be president."

Within hours, UK diplomats began to sense that their entreaties were either having no effect, or could even be rebounding on Blair's chances of success. They acknowledged that the former prime minister's hopes of European glory were fading, but insisted they had been right to champion his candidacy. It was in Britain's – and Europe's – interests to have one of the world's best-known politicians in the job. Before French president Nicolas Sarkozy dealt his blow to Mr Blair's hopes, chancellor Merkel told German reporters during her traditional "fireside chat" in Brussels on Thursday that the question of Blair's candidacy had all but resolved itself thanks to the Spanish prime minister. José Luis Zapatero, she said, had waged the war on her behalf by declaring that European Socialists hankered after the No 2 post of EU high representative. By definition, this means the coveted presidential prize should go to the Christian Democrats, whose hopefuls include Dutch prime minister Jan Peter Balkenende and Luxembourg's Jean-Claude Juncker.

But the anti-Blair front that has developed is merely the result of months of tactical errors by his campaigners. Not only did his envoys not win over Paris and Berlin, but they also, it seems, forgot about the need to get the EU's smaller states behind them. "To us, it seemed like the game was all about the big boys. But that's not the way that the EU works any more," said one diplomat from a Baltic state. "We were not consulted even though we were aware of lobbying for Blair, which had started already way back in the summer, far earlier than anyone else." The diplomat expressed surprise at this clumsy approach. "It's very odd, as Tony Blair had a terrific team of EU advisers when he was in power, which is how he got so much done. But clearly that's changed."

The campaign for Blair also suffered from a brazenness that is not in tune with the more subtle approach to diplomacy á la Européenne. It was also suggested the Blair campaign probably started too early, giving opponents too long to attack.