By Nick Assinder BBC News Online political correspondent

Twelve months ago, the annual TUC conference was abandoned in the wake of the 11 September atrocity.

Tony Blair had been set to make a crucial speech amid growing revolt by the unions over his plans for the public services.

It was being billed as one of his most difficult appearances yet as prime minister.

Concern over relationship

The New Labour honeymoon was well and truly over and Mr Blair was facing the wrath of those who should be his natural supporters.

But no one wanted that confrontation to take place just hours after the trade centre attack.

Anger and suspicion

The speech was dropped and the conference scrapped as domestic issues were put to one side.

	:	Trade unions guide
The big unions at TUC 2002

Delegates left the conference to headlines such as "TUC showdown postponed."

This year, 11 September will once again hang over the conference, but this time the showdown cannot be avoided.

The prime minister will have to face that union anger and suspicion at his hugely-controversial plans to allow the private sector into the public services.

If anything, the strains between the unions and the government have intensified over the past year.

There is the ongoing threat of industrial action in the public services and some unions have cut their donations to the Labour party in protest at Tony Blair's policies others have withdrawn sponsorship to individual MPs.

Biggest revolt

But by far the most dangerous issue for the prime minister is the fallout from those events in the US one year ago.

His readiness to stand shoulder to shoulder with President Bush in the international war against terrorism has seen him criticised by union members, many of who are dismayed at his closeness to a Republican President.

Pensioners are a growing force

More importantly, his apparent willingness to join President Bush in military action against Iraq has threatened the biggest revolt yet against his government.

And while the row over the public services, the minimum wage, the euro and union influence in government will most certainly erupt at the conference, the possible war on Saddam will dominate.

It is being seen by many as the final straw, the clearest possible example of how far New Labour has moved away from its union roots.

Even the government's bid to avert the worst by floating the idea of imposing a deadline on Saddam to re-admit weapons inspectors will not see off a revolt.

It is hard to find a single union voice in support of action against Saddam and many are deeply frustrated that, once again, the prime minister does not appear to be listening to them.

Pensions poverty

It may well be that all the anger and frustration over the public services will be given a focus though the opposition to war.

Meanwhile there will also be key debates on Britain's possible entry into the single currency and demands for the prime minister to announce a timetable for the promised referendum on the issue.

Monks is retiring

There is also the continuing row over pensions and the fears that the next generation of pensioners will face real hardship.

And the conference comes at a time when the New Labour voices in the movement, such as John Monks, are on the wane and the left, in the shape of leaders like Amicus' Derek Simpson are gaining ground.

So the prime minister has a major challenge on his hands during this year's conference season.

But there is no sign so far that he is about to back down on any of the key concerns.

The wreckers

He is expected to repeat his insistence that reforming the public services is his top priority and that he will not be deflected from that task.

And he will say that the government is now pouring cash into the services but that investment must be met by reform.

Labour and union members will be particularly sensitive to the language he uses during the conferences.

They have been angered by his past suggestion that some of them were the "wreckers" or "forces of conservatism" who were standing in the way of reform.

If he uses similar language this year he will only further inflame feelings against him.

Last year's confrontation may have been postponed - but it cannot now be avoided.