David Davis sees himself as a heroic figure. The Shadow Home Secretary, in his mind, is fearless. He is bold. He is brave. I’m sure he thinks it was Ian Fleming’s loss that he didn’t have the chance to base James Bond on him. As it is, DD doesn’t think much of Bond. Surely “shaken not stirred” is for wimps. He prefers “shaken and stirred”. Life is about more than a Martini.

It is all faintly ludicrous (though not to him) but the fact is that he has seen off three home secretaries. Yesterday, as MPs debated the home affairs portion of the Queen’s Speech, the fourth one sat across from him. Up until now, everyone has treated Jacqui Smith with kid gloves. She is known as a nice person. Plus – and it’s still seen as close to incredible – she’s a she. Most men here don’t know what to do about that. She’s not a shrew and so how do you attack her?

The debate began in a lackadaisical manner. DD had struck his usual lounge-lizard pose, feet propped up against the dispatch-box table. Ms Smith sat across, busily making notes, looking like the schoolteacher that she used to be. I didn’t expect much from DD, for he can be as careless as a teenager with his arguments. So it was all the more shocking to find myself hearing the best speech I have ever heard him give.

It was a declaration of war on the Government’s plans to extend detention for terrorist suspects. DD did not stop with a warning shot. He loaded the cannon and let rip. He was a man possessed. It dawned that he might actually care about this. You’d be surprised how rare that is at Westminster.

Ms Smith, he noted, had never explained why she wanted to go beyond the current 28-day period. Indeed, she had told the Home Affairs Committee: “There has not been a circumstance in which it has been necessary up to this point to go beyond 28 days.” Ms Smith, on the front bench, muttered: “Thank goodness.”

This inflamed DD, who turned on her, teeth bared, like a dog with the hair standing up on the back of his neck. “She seems to have managed to pick this number out of the air!” he cried, referring to 28 days. “The highest number in the free world! The highest length of time for people to be held without charge in the free world! Hardly a matter of pride for her to pick on! So we’ll come back to her in a minute!”

He railed on. There was no proof that the police needed more time. He inferred that she knew nothing about computers or, actually, much else. She looked on sourly, no longer taking notes.

“Extending detention without trial will undermine our freedoms but it won’t make us safer,” said DD, his voice trying to become sonorous. If only this had been a movie, he could have been helped by the first few stirring chords of Jerusalem.

“I look around the chamber and almost everybody here is wearing a poppy,” he noted. At this, MPs looked down at their poppies. The few without them looked alarmed.

“Those poppies symbolise an enormous sacrifice,” said DD. “Our freedom was bought at a very high price. We on this side will not give those freedoms away without very good reason.”

DD sat down to shocked silence. Shaken and stirred indeed. It’s going to get nasty.

Times Recommends

• Time-worn Freddie gives up Test matches
• Brighton company 'involved in cyber attack'
• The art of survival: it’s all in the mind