The call for restraint in "the next few crucial months" comes in a letter from the party chairman, Ian McCartney, to the organisation bringing together Labour affiliated unions, the Trade Union and Labour Party Liaison Organisation (Tulo). It is the clearest sign yet that the leadership expects the election soon.
The letter underlines government fears that strikes over pension cuts, especially in the public sector, could provoke a spate of damaging headlines. The public sector union, Unison, is holding ballots in connection with claims that the deputy prime minister, John Prescott, is cutting pension entitlements. Similar strikes are possible in the NHS after proposed changes published this week.
Mr McCartney's letter, dated December 20, to Tony Dubbins, Tulo co-chairman, warns: "I should like to bring your attention to a number of headlines that emerged last week on the issue of threatened industrial action over pension reform in the public sector.
"I know you will agree with me that these issues are much better addressed through dialogue rather than confrontation, and I hope we can encourage an improved spirit of partnership over the crucial next few months."
He adds: "I know the strength of commitment that exists to delivering the third term among union colleagues - I look forward to making that a reality over the coming months."
Mr McCartney's letter is designed to reassure sceptical unions that an agreement reached at a party policy forum in Warwick in the summer will be fully implemented and reflected in the manifesto.
The Conservatives claimed last night that it revealed that a weakened Tony Blair was no longer able to keep his commitment that he would offer the unions only fairness not favours.
Unison fears the Warwick agreement will be watered down into a set of vague aspirations. The unions are especially worried that reforms designed to ensure rights for workers will be undermined by more private sector contractors in the public sector.
Mr McCartney seeks to reassure the unions that the government is sticking by the Warwick agreement, pointing out that the right for a workforce not to be sacked for industrial action has been extended from eight to 12 weeks. He says the women at work commission on equal pay has started meeting regularly with significant union representation. He adds that he has already implemented a promise that 50% of pension scheme trustees are membership-nominated. He also asserts that the chancellor's pre-budget report in the field of childcare and parental leave has gone beyond the agreed words in Warwick, as has the Department for Education with £1m more capital funding to back union learning projects.
In one of the most contentious areas of public sector reform, Mr McCartney insists that it is now agreed government policy to end the system in which workers employed by the private sector are paid less than those in the public sector.
He concludes: "Warwick will be implemented - but only if Labour wins the historic third term we all cherish."
The TUC's Public Service Liaison Group yesterday agreed on February 18 as a nationwide day of campaigning for union members to voice concerns over pension rights.
