Today's meeting sees prime minister Gordon Brown in a much weaker condition than Tony Blair was back in 2004. So if you thought his promises of longer holidays, more maternity pay and equal rights for temps were too much, you won't like what is about to happen.

On the face of it, Labour's programme is being agreed over the course of the weekend in the fairly open environment of the party's policy forum. In practice, of course, there will be much behind-the-scenes manoeuvring and, one might surmise, more than a little horse-trading.

Unlike the old days, when unions held a majority of the votes and Labour's annual conference was the forum for policy making, the unions now hold only 25% of the votes.

However, they may find some sympathy among constituency delegates - and among the growing number of Labour MPs who now, for the first time, face the real prospect of being booted out of Parliament at the next election.

Furthermore, with business now swinging back behind the Tories, they are likely to be pretty much the only source of cash Labour can turn to. And the unions need to show that their cash buys influence because activists are getting restless about where the money is going.

The issues where the unions want to see things change are reasonably clear. We ran a list in this blog a couple of months back, and that is brought nicely up to date by David Hencke's article in today's Guardian.

But ministers are also clear about the things they don't want to see in their next manifesto: the legalisation of secondary picketing and compulsory equal pay audits for private sector companies among them.

Quite whether the promise of "environmental shop stewards" and a few more flexible working options will be enough to keep the unions onside remains to be seen.

Picture: Ken McKay/Rex Features