Tony Blair was once forced to plead with Gordon Brown for a hint about what was in his imminent Budget, according to the memoirs of a former Downing Street economics adviser.

In his book, Off Whitehall, Derek Scott says that shortly before the 1998 Budget the chancellor told an inquiring prime minister: "I haven't made my mind up."

That produced a desperate, "give me a hint Gordon" from Blair.

"It soon became known throughout Whitehall that, in some areas at least, the chancellor could defy the prime minister with impunity," Scott claims.

The Scott book also presents an image of an "obstructive and deceitful" chancellor.