A series of controversial draft motions, which will be submitted by today's deadline, will ensure that the Prime Minister and the Chancellor, Gordon Brown, face a rough ride at the annual assembly, which begins a week on Sunday.
The resolutions, which have been seen by The Independent, are almost guaranteed to be passed. They will win the overwhelming support of unions, which hold half of the votes, and are also expected to attract backing from constituency delegates. Union leaders will seek retribution on Tony Blair and Mr Brown, who lectured them on the need for modernisation at this week's TUC conference.
The party's assembly is also expected to pass a resolution condemning the increasing role of the private sector in the health service and another calling for British workers to enjoy the same employment rights as those on the Continent.
The motion on pensions however, tabled by the GMB general union, will strike the biggest chord with delegates at a time when employees believe their benefits are being severely undermined.
On Wednesday, leaders of 13 unions warned of industrial action by three million public-sector workers if the Government increases the retirement age to 65. The motion accuses the Government of an "attack'' on public sector pensions.Alan Johnson, the Trade and Industry Secretary, is due to meet employees' representatives on Wednesday as part of the negotiations.
The resolution will call for compulsory contributions from all employers and employees and an extension of the financial assistance scheme which helps workers where retirement funds are in difficulties.
In a separate proposal, the Transport and General Workers' Union will accuse management at the catering company Gate Gourmet of "pre-planning" the dispute which led to the dismissal of hundreds of workers. It will demand a law to allow supportive industrial action where there is a "close connection" between two sets of workers. Baggage handlers at British Airways, which is Gate Gourmet's main customer, unlawfully walked out in sympathy with the employees dismissed by the catering company.
Under the proposals, strike-balloting procedures would be simplified and strikers protected from dismissal and replacement.