They were clutching pints of beer, but they must have been tempted to crack open the champagne. The union barons Derek Simpson and Tony Woodley were all smiles in the gleaming bar of the Radisson Hotel hours after Ed Miliband clinched his dramatic leadership victory.
The joint general secretaries of Unite, Britain’s biggest union, had earlier taken their teams out for a celebratory dinner to mark the result. The mood around the restaurant tables was euphoric – for the first time since the early 1990s the union top brass believes it has the ear of the Labour leader. As one offiical said: "We stopped David - that's the main thing."
Unite’s intervention in the contest proved crucial. The leadership enthusiastically endorsed Ed Miliband's candidacy and urged its members to back the younger brother. They duly voted by a margin of well over two-to-one in favour of Ed, providing a groundswell of support that swept him over the finishing line.
Members of two of the other largest unions, the GMB and Unison, also voted decisively for Miliband Jnr after their leadership endorsed his candidacy.
Britain’s union establishment will now be hoping to secure his fulsome support for its resistance against the coalition government’s cuts – ultimately likely to include industrial action.
Between them, members of Unite, Unison and the GMB cast nearly three-quarters of the votes in the union section – or equivalent to 25 per cent of the entire Labour electoral college.
When the leadership campaign got underway, the Unite leadership was naturally veering towards supporting Ed Balls, believing he would take the party decisively to the left. But as David Miliband built an early lead and their man’s hopes faded, they settled on Ed Miliband as best-placed to beat his older brother, who the unions regarded as the Blairite candidate.
Talks with Unison and GMB top brass over the summer arrived at the same conclusion: they had to group around Ed Miliband as the most credible “stop David” man. The formal endorsements of all three unions followed, dwarfing the decision of the shopworkers’ union Usdaw to come out for David.
Their tactics have provoked controversy – and indignation verging on anger – in David Miliband's camp as they were accused of bending party rules to maximise support for Ed.
Unite included a leaflet pledging its support for Ed Miliband along with the ballot papers, while the GMB sent out voting form in packages urging its members to back him.
They went further and set about maximising their candidate’s support among MPs. During the TUC conference in Liverpool two weeks ago, union officials targeted MPs planning to support Ed Balls, Andy Burnham or Diane Abbott, urging them to give their second-preference to Ed Miliband.
Charlie Whelan, Unite’s political director, yesterday shrugged off a report that he persuaded six MPs at the conference to place Ed Miliband second. If accurate, that could have been the difference between victory and defeat for the brothers.
Their cause was helped when David Miliband was the only candidate to hesitate when they were asked at a packed hustings meeting in Liverpool whether they would attend a planned anti-cuts rally.
Later that evening in a BBC interview he confirmed he would be among marchers. But the damage was done – union activists were already fuming in the bars over his ambiguous answer.
A detailed breakdown released yesterday of how trade unionists’ first preference votes were cast underlined the strength of Ed Miliband’s lead over his brother. He led by 47,439 votes to 21,778 among Unite members, by 18,128 votes to 9,746 among GMB members and by 9,652 votes to 6,665 votes among Unison members.
The unions were unrepentant about their tactics, arguing that they were simply levelling the playing field. One union source said yesterday: “David had the big money, his team was vastly bigger than Ed’s. He had been preparing for this moment for years and he had the backing of the media. The unions were counteracting that.”
The unions also argue that Ed Miliband won the day because he was more in tune with the working class – a key demographic at the next election.
Mr Miliband now faces tricky decisions over how close he moves towards Messrs Simpson, Woodley, Prentis and their like. He owes them much for his victory and his cash-strapped party will rely heavily on their largesse in the years ahead.
But he will also be conscious of his vulnerability on the issue. Baroness Warsi, the Tory chairman, taunted him for being “put into power by union votes”. The charge will repeated ad nauseum by his coalition opponents.