According to the Daily Telegraph, union leaders have delivered a blow to Blair's hope for EU constitution - the TUC last night having refused to give its backing to the campaign for a Yes vote.
Apparently, a "heated debate on the constitution" at the congress in Brighton exposed deep splits within the union movement over the direction in which Europe is moving - leaving it unable to endorse the Government's pro-constitution policy.
Says the Telegraph, "without the support of the TUC, representing more than six million voters, ministers know that they have almost no chance of winning a referendum, likely to be held in 2006".
Fearing that a vote in favour would be lost, TUC organisers issued a holding statement saying it was "inappropriate" to adopt a formal position before further debate.
This represents a significant turnaround from the Thatcher days when, on 8 September 1988, Jaques Delors was invited to address the congress and wowed them in the aisles with his talk of a "social dimension" to Europe.
However, the union message is somewhat muddled, with Bob Crow, the general secretary of the Rail, Maritime and Transport Union, objecting to the constitution on the grounds that it would "institutionalise privatisation and the neo-liberal economics that have helped wreck industries in Britain and turned the EU into one of the world's low growth regions", a message which is hardly likely to appeal to right-wing Eurosceptics.
His message very much reflects the muddled thinking of the Centre for Social Europe and there remains a view that with friends like that, the “no” campaign will not have need of any enemies. After all, it was union opposition to the EEC is 1975 which was instrumental in swinging the country to support the "yes" campaign.
Now, opposition from the bigger unions, including the Transport and General Workers and Amicus, the private sector union, who are considering campaigning for a "no" vote, on the basis that the constitution does not guarantee that British workers to get "equal rights" to those on the Continent, could have the same effect.
By contrast, when the likes of John Monks, a former congress general secretary who now heads the European TUC, accuses the left of "making common cause with Michael Howard and the Tories in opposing Britain's wholehearted engagement in Europe", he could actually be favouring the Eurosceptic cause.
Altogether, Union support for the "no" campaign could be a mixed blessing. If success in politics depends as much on making the right enemies as it does making the right friends, it is possible that we would be better off with them on the other side.