Peter Mandelson's departure from the Northern Ireland office at such a crucial time in the peace negotiations ups the pressure on the prime minister.

Mandelson, who carried no ideological baggage on the Ulster question, soon won the respect of David Trimble - however his relations were less cordial with republicans, who in recent weeks have circumnavigated Mandelson, making their case directly to the prime minister instead.

John Reid, an accomplished political fixer who is close to Blair, will arrive in Northern Ireland today where he will have to work with skill and cunning to secure a deal ahead of next week's unofficial deadline.