Clare Short told me she thought it would be very sad if he was just supporting the Prime Minister out of loyalty. This is, of course, a totally naive approach to politics.
There is no doubt Brown thought his open attack on Blair last month for refusing him a position on Labour's National Executive Committee was a PR disaster. The Chancellor's main reason for this was that a few commentators and leader writers had attacked him for being disloyal.
Given that these people, known as the 'Islington set', have never supported the Chancellor and have been craven in their support for Blair, you could have forgiven Brown for ignoring them. Ironically, the very same people really don't support Blair over tuition fees, but are united in their hatred of Brown, probably because he never bothered to attend their dinner parties.
Despite this, the Chancellor has now decided he will only become Prime Minister by being 100 per cent loyal, and it's easy to see why. Just look at recent history. We all knew that Michael Howard thought Iain Duncan Smith was a bozo, but pretending to support him helped the top job fall into his lap. But look what happened to the less patient Michael Heseltine.
Ironically, Tony Blair's supporters are so suspicious of Brown's solid support for the Prime Minister over top-up fees they now suspect a sinister plot by the Chancellor. Some of his supporters even think a new deal has been done over the leadership - as if Brown would fall for that old trick.
Watching my old boss on Breakfast with Frost, though, I could tell his heart was not in this. There is no way he really supports 'variable fees', and what he told Frost only confirmed it. Unlike Blair, Brown does not lie very well. In fact, he can't do it at all. When asked directly about variable fees, the Chancellor's body language changed immediately and he came out with a well-prepared mantra: 'Tony Blair has said that the variable fee is part of the system, and I can see how a variable fee can be complemented.' So does he support it? Of course not. That's why he says it's either Tony Blair or Charles Clarke's idea.
Brown's other good reason for pretending to back the Prime Minister over this issue is that he believes Blair will probably win. He knows how spineless most Labour backbench MPs really are. They supported foundation hospitals, which were overwhelmingly opposed by the party conference, and even supported the Iraq war despite near universal opposition from Labour Party members and the biggest demonstration in history. Even if Blair was to lose this vote, and he still might, the vast majority of Labour MPs would have backed Blair. Brown will need their support if he is to take over as Prime Minister.
Despite his pleas, many of Brown's friends will still refuse to back Blair - and who can blame them. Some - like Nick Brown, a long-time supporter of the Chancellor, who was sacked by Blair - have every reason to try to bring the PM down. None of them will criticise Brown for his actions, though. Others might. The traditionally friendly Daily Mirror has been scathing already, and who can blame it: the Chancellor's spin doctors decided to place a major interview about baby Brown and the Chancellor's support for Blair in The Sun.
Someone should tell them that upsetting your best friends is not good PR.