Within the Shadow Cabinet, Mr Cook was its most outspoken critic of Mr Blair's determination to replace the clause. His conversion, to be set out in a keynote speech in Westminster, will boost the Labour leader's mission while coming as a blow to the left, who have traditionally viewed Mr Cook as their standard-bearer.
In the speech, he will admit he was initially opposed to the change but has now come round to the view that it is very much needed, and will highlight what he now accepts are "many curious omissions" from the clause, including equality, solidarity, demo cracy and social justice.
Mr Cook will say that Sidney Webb, author of the clause in 1918, would be amazed if he came back now and found it unchanged.
He will go on to remark that that "public ownership is not the sole objective of socialism" and Clause IV should not be "pickled in vinegar". Labour's ideology rests not on state ownership but on social solidarity, he will declare.Reuse content