The Labour leader's opponents appeared resigned to defeat at the special conference next April, against the trade-union block vote.
But they warned Mr Blair that he had ensured the battle would continue at every party conference until the end of the century. Tony Benn said there was strong grass-roots support among the constituencies for taking the privatised utilities back into public ownership.
"We have got to bring the railways back into public ownership, if they are privatised, the water industry, and gas. The public services have got to be publicly owned to be more democratic," he said.
Mr Blair's supporters on the right said the constituencies' rebellion had been overstated. "Some will back him just to show they support his leadership. He will win in either case, the unions will see to that," said one right-wing Labour MP.
Peter Snape, MP for West Bromich East, who handled the successful by-election campaign in Dudley West, said: "Clause IV was not an issue on the doorsteps but if the Bennites are saying it is impossible even to discuss these matters, then we should not besurprised. They are the same people who have been opposing successive Labour leaders since Harold Wilson."
Mr Benn stepped up the opposition to Mr Blair's reform at a press conference in Westminster held by a co-ordinating committee to defend the clause, led by Arthur Scargill, the miners' leader, and supported by the Campaign group of left-wing Labour MPs. James Mortimer, former party general secretary, called Mr Blair's plan to reform Cause IV "divisive and unnecessary".
David Winnick, MP for Walsall North, who is not in the Campaign group, said: "It would be an impossible situation if the leader put forward a point of view and we all said we cannot do anything about it."
It was an error of judgement to believe that somehow the "situation can be stitched and the members might be stitched", said Alan Simpson, MP for Nottingham South and chairman of the Campaign group.
In spite of signals that they will be defeated, activists are still optomistic that they can secure enough support from the unions to win. Tom Rigby, who campaigned against the leadership in the one member, one vote (Omov) battle last year, said he expected Unison, the Transport and General Workers' Union and the Rail, Maritime and Transport union to vote against any change. He said that although Tom Sawyer, a Unison leader, had become general secretary of the Labour Party, other key executive members of the public-service workers' union were opposed to reform.
The transport section of the TGWU had proposed public ownership for bus services at a conference in July and the general committee of the union was left-led, he added.
Usdaw, the shop workers' union, had voted for the leadership at last year's conference on Omov, against the wishes of a consultation conference. Mr Rigby said it could not do so again. "Clause IV is supported by right and left. Bill Morris and John Edmonds have been noticeable by their silence," he said.
A compromise, to keep Clause IV but to insert new phrases into the constitution setting out aims and values, is being canvassed by the left.
Leading article, page 17