Tony Blair on Wednesday dramatically ended long-running speculation that he would try to switch Gordon Brown to another job after polling day, in a move that boosts the party's poll hopes and Mr Brown's own chances of one day succeeding to the premiership.

Acting to end months of bitter rivalry with his principal ally in the formation of New Labour, the prime minister said it would be “foolish” to move Mr Brown from the Treasury where he has held sway for the past eight years.