Sticking up for failed suicide bombers won’t win you a popularity contest on the No 30 bus. But Shami Chakrabarti, spunky leader of the human rights group Liberty, has won grudging respect from her critics for the way she is opposing the government’s terror crackdown. The reason? She’s a straight talker.

“I am morally comfortable with the idea of shooting to kill,” she tells me. “In extremis you take life to defend life.” Far from being earnestly PC, she chirpily swipes at “mad mullahs”. More likely to be found with a microphone than a “stick it to the pigs” badge adorning her designer lapel, she angered her supporters by urging understanding for police after they shot dead Jean Charles de Menezes, the Brazilian electrician.

That moderation means that her words carry more force now as she uses this interview to call for Sir Ian Blair, Metropolitan police commissioner, to “consider his position” for burying the Brazilian’s reputation before his body was cold, in a PR performance so cynical that it would make Jo Moore, the former spin doctor, blush. But Chakrabarti needs to be hauled in for questioning, too. She denounces ministers for being insensitive to the needs of jihadists, but how would she make us safer?

The first thing you notice about Chakrabarti is: if she is the biggest obstacle to draconian anti-terror measures from Charles “five bellies” Clarke, then she isn’t a terribly big obstacle. A wedding photograph in her south London sitting room shows her enveloped in the bulky arms of her (white, City lawyer) husband. But as soon as she speaks and fixes you with piercing eyes, you realise she is no mouse: what does she make of her predecessors, Harriet Harman and Patricia Hewitt, both now ministers?

“There are people in government supporting measures they would never have supported in their youth.” And she has a fine riposte to the prime minister, who plans to prosecute those who justify terrorism: “Then he must lock up Cherie.”

Cherie Blair has said that she understands how Palestinians might be driven to violence. The same, Chakrabarti says, goes for anti-Saddam Hussein exiles whom Tony Blair has helped into power in Iraq.

We begin in tough-cop mode: so then, Shami, me old mate, you oppose the racial profiling of Asian terror suspects, yet it was hunky-dory to assume IRA terrorists were Irish. Why?

“If there are images of suspects then those are the people you are looking for; that is intelligence-led policing.”

No it isn’t. Intelligence-led policing is catching the blighters before they attempt to let off their fireworks.

“Racial profiling says there is a greater probability that a particular racial group is more likely to plant a bomb,” she replies. So it only states the bleeding obvious, then; bombers tend not to be, in the famous phrase, “little white old ladies”.

“But that means you are going to treat one group differently, potentially for years,” she bats back.

So should police search by quota? If, say, 55% of the population is white, should 55% of those frisked be white?

“Well, if you go down the route of two queues at the Tube station you start telegraphing to terror groups what your MO is. Then the white girlfriend can be persuaded, menaces can be used, to get other people to carry bombs.” Well, yes, in that scenario searching would need to be broadened.