As they returned to their desks from their summer break, Tony Blair's aides wondered what frame of mind Gordon Brown would be in after his holiday.

As they returned to their desks from their summer break, Tony Blair's aides wondered what frame of mind Gordon Brown would be in after his holiday.

Yesterday they got their answer. Mr Brown, who had good reason to believe he might be anointed Labour leader at the party's annual conference later this month, apparently still feels grumpy about Mr Blair's latest Houdini-like recovery before the summer recess. And he is very grumpy indeed about the Prime Minister's plan to install the uber-Blairite Alan Milburn as Labour Party chairman. To the Brown camp, that is a declaration of turf war because the Chancellor is supposed to be in charge of general election strategy.

The Blairites accuse Brownites of leaking the plan to recall Mr Milburn to Sunday newspapers in the hope of creating a backlash that would scupper it.

The charge is denied by the Brownites, who point out that the initial stories about Mr Milburn's planned appointment were "sympathetic" to the former health secretary.

Politics is back, and so is the Blair-Brown saga. The plot thickened last night with the surprise resignation of Andrew Smith, the Work and Pensions Secretary and a key Brown ally. The unanswered question is: why did he not wait for Mr Blair's Cabinet reshuffle, expected later this week?

As ever, the Blairites scent a Brownite campaign to undermine the Prime Minister ­ this time by turning the Cabinet shake-up into a repeat of last year's fiasco, when the resignation of Mr Milburn as health secretary forced Mr Blair to stumble into the most messy reshuffle in recent history. The Prime Minister announced the abolition of the ancient post of Lord Chancellor, only to find he could not do so without legislation. His hasty attempt to scrap the posts of Scottish secretary and Welsh secretary created further confusion.

The Blair camp's suspicions were fuelled when the former Labour chief whip Nick Brown, one of the Chancellor's closest allies, popped up on last night's Channel 4 News to say Mr Smith's departure, would "significantly weaken" the Government. Asked if he thought this week's reshuffle was being well run, Nick Brown replied: "I think it is as well ordered as last year's."

Nick Brown also attacked the anonymous briefings against Mr Smith which were one factor in his decision to leave the Cabinet before he was pushed out the Department of Work and Pensions to another post.

Nick Brown added: "There are other ministers that are being briefed against and so I assume they are in trouble as well." This was a reference to Ian McCartney, the Labour chairman, whose position had seemed under threat until last night when he came away from a meeting with Mr Blair with the "understanding" he would be staying in his post.

Where will the latest outbreak of what Labour MPs call the "TB-GBs" end? Mr Blair might have contemplated resigning before the election at peace talks with the Chancellor, chaired by the Deputy Prime Minister John Prescott, last November. But he feels that he has "come through the fire" and is determined to carry on.

A newly-confident Mr Blair will demand pre-election unity when he addresses the TUC and Labour conferences in the next few weeks. There will no doubt be speculation that Mr Blair will move Gordon Brown from the Treasury ­ if not now, then after the general election. It almost certainly won't happen, and they will continue to muddle along, as they always do. The Blair-Brown saga has a few more acts to run.