It says something about the febrile state of today’s Labour party that Jacqui Smith, Britain’s first woman home secretary, has been transformed overnight from misfiring member of the cabinet to future leader – on the back of a single speech.

The oratorical tour de force was delivered on Monday night to a packed private meeting of Labour MPs and peers, when Ms Smith somehow lifted the surly mood of the party and softened opposition to the controversial plan to extend pre-charge detention to 42 days.