Anti-war campaigners are today set to turn up the heat on the prime minister.

The left wing Campaign group, which represents 40 Labour MPs, has called on the prime minister to consider his position.

A statement from the group warns: "We are now placing at risk the entire fabric of the international community. Blair is not the issue, the future of the UN is."

A union source told today's Guardian that "there will be mayhem" if Blair goes to war without the backing of a second UN resolution.

Labour MPs will use prime minister's questions to urge restraint.

They will seize on Donald Rumsfeld's remarks to signal that Britain now has an exit strategy.

Blair yesterday held crisis talks in Downing Street with senior ministers and defence chiefs.

Today's Sun rounds on the Labour rebels. Its editorial says: "How dare this bunch of wobblers and whingers tell Tony Blair he should 'consider his position' as prime minister... Once this war is over there will be debts to settled. We will never forgive the French, the Russians or Labour's wimps."

The FT examines the prime minister's seven key advisers and concludes Sir David Manning is the man masterminding the current strategy.

Meanwhile the Times reports on the "ultimate gamble" facing the prime minister.