The party leadership forced the cancellation when it became clear that the NEC wanted to support delegates campaigning against proportional representation in tomorrow's crucial debate on the voting system.
The NEC embarrassed the Prime Minister last month when its official submission to the Jenkins Commission, which is looking at the issue, came out strongly against reform and complained that PR led to permanent coalition.
However, the prospect of the party's ruling body giving official approval to one side of the increasingly acrimonious dispute prompted officials at Labour's Millbank headquarters in London to intervene at the last minute.
The meeting was due to go ahead at 7.30am yesterday, but The Independent understands that party officials panicked and placed notes calling it off under NEC members' hotel doors at 2am.
It also emerged yesterday that the set-piece debate on the issue, tomorrow, will now be as short and low-key as possible under a deal between PR opponents and Mr Blair's aides.
Hardline anti-PR unions wanted a conference vote on the issue, but it became clear that the engineers union, AEEU, which is moving the motion, did not want to embarrass the Prime Minister. The motion, which urges Labour to back the first-past-the-post system, was eagerly awaited by pro-reform and anti-reform groups.
The compromise deal will give campaigners the chance to make their views clear but no vote will be taken.Reuse content