Brown creates open-plan war room at No12

In a clear signal that the Prime Minister intends to use the financial crisis to stamp his authority on the Government, he has installed himself at the heart of the new office so he can oversee co-ordination of the No 10 machine.

The move, which ends centuries of tradition where ministers and civil servants hid in their own rooms is modelled on New York Mayor Mike Bloomberg's set-up. It means that Downing Street will be effectively put on a permanent "war footing" as Mr Brown becomes the first world leader to put himself in the middle of his senior staff.

Regularly at his desk from before 7am, he began today in his new office before chairing the Cabinet meeting and then heading off for a photocall on helping business cope with the downturn.

The new open-plan arrangement has been set up in the former press office in No 12 Downing Street, the only room big enough to accommodate the changes.

At the heart of the room is an elongated H-shape of desks, with Mr Brown seated in the middle and his Permanent Secretary Jeremy Heywood sitting to his left.

Cabinet office ministers Liam Byrne and Tom Watson will spend their working day near to the Premier, seated just alongside Mr Heywood. On Mr Brown's right sits policy adviser Gavin Kelly, while further up the room is Nick Pearce, the head of No 10's strategy unit.

A huge flat-screen TV has been mounted on the far wall facing Mr Brown to ensure that the office is constantly updated with 24-hour world and domestic news.

Opposite Mr Brown sits his principal private secretary James Bowler, while a more traditional "gatekeeper's" desk is taken by his personal secretary Sue Nye.

Adjoining the "war room" is a specialised press and media room.

Mr Brown still retains a private office, but it is used only for writing speeches. Until this week, the PM worked from a "den" upstairs at No 10 but he was constantly frustrated that he was physically isolated from staff.