Bill Morris, head of the left- wing Transport and General Workers' Union - Labour's biggest affiliate - refused to be drawn into condemning Mr Blair's vision of the party.
Mr Morris, whose union was expected to be among the leader's sternest critics, said he would not form a judgement until he saw the detail of Mr Blair's plans. He believed the Labour leader was simply drawing up a 'mission statement' rather than making a fundamental change.
Last night, Peter Hain, the left-wing MP for Neath, was unrepentent about his support for Clause IV. He said: 'It speaks of 'common ownership' - not state ownership - 'of the means of production, distribution and exchange, and the best obtainable system of popular administration and control of each industry or service' . . . What's wrong with that?'
Jack Straw, who published his own proposals for a revised Clause IV in 1993, said the re-writing would be 'a collaborative, consultative venture. The party has to debate and agree what its aims and values are.'
John Edmonds, the general secretary of the GMB general union, which is the second largest affiliate, said he would have no quarrel with a replacement Clause IV if it reflected the sentiments in Mr Blair's 'excellent' speech.
A GMB delegate summed up the mood of many of his colleagues when he said Clause IV had never been implemented by a Labour government and that a re-examination of it was inevitable.
The reaction of other union leaders ranged from the predictable fury of Arthur Scargill, who said Mr Blair had declared war on the Labour Party, to the endorsement of Bill Jordan, right-wing leader of the Amalgamated Engineering and Electrical Union.
Roy Hattersley, former deputy leader, said Mr Blair was 'absolutely right' to look again at the constitution, and said he hoped Clause IV would go: 'I think it will be a popular thing to do and a wholly right thing to do.'
One Shadow cabinet minister said the inclusion of John Prescott in the re-working of the constitution was to reassure doubters on the left: 'He will take the fire.'
Some MPs on the left were reassured by Mr Blair's commitment to keeping railways and the Post Office in the public sector, suspecting the re-writing would involve a re- casting of a commitment to at least some public ownership rather than a wholesale dumping of the clause.
Bernie Grant, the Tottenham MP, said he was delighted that Mr Blair had rehabilitated the word 'socialism' in his speech, and that it might be possible to find something 'more appropriate' to replace Clause IV.
Giles Radice, the MP for Durham North who is on the party's right and has campaigned for the clause to be re-written, said Mr Blair's move 'shows what a very courageous leader we now have'.
One member of the Shadow cabinet said: 'It's a bold and brave gamble. I just hope it bloody works.'Reuse content