Tony Blair has rejected claims that the UK is a "police state for Muslims" as "categorically wrong".
Mr Blair's spokesman said a police state would not have freed Mr Bakr
Abu Bakr, who was arrested, questioned and then released without charge over an alleged kidnap plot, made the remarks on BBC Two's Newsnight.
But the prime minister's official spokesman said anyone arrested in a police state would not have been freed and allowed to appear on television.
He said: "It is a gross caricature of the political process in this country."
Chancellor Gordon Brown described Mr Bakr's comments as "unacceptable".
Commons leader Jack Straw also attacked the claims during business questions in the Commons.
He told MPs: "We should not give excuse or quarter to those who claim this country is a police state - that is absolute, utter nonsense.
"We live in a democracy and what we are sadly having to fight at the moment is people who seek to destroy the very basis of our democracy."
Mr Bakr, from Birmingham, when asked about his arrest, questioning and subsequent release without charge, had told the BBC: "It's a police state for Muslims.
"It's not a police state for everybody else because these terror laws are designed specifically for Muslims and that's quite an open fact."
A spokesman for West Midlands Police said it was normal that some people would be arrested and released without charge in large and complex criminal investigations.
Mr Bakr, who is studying for a PhD in Political Islam, said he became aware of the police forcing their way into his house early on Wednesday last week by his wife screaming.
'Hard to readjust'
He added that he had been released by police a week later and told to "go back to things how they were".
"But they don't realise that, after seven days of virtual torture for my family, it's going to be hard to readjust," Mr Bakr said.
"This is going to affect me for the rest of my life."
Mr Bakr said his parents had told him they had aged 10 years while he had been in custody.
He also criticised what he called "amateur-type interrogation" by the police who, he said, had subjected him to "random questioning" about notes written on pieces of paper by his young children.
Conservative leader David Cameron denied the law singled out Muslims.
He said: "The terror laws apply to everybody, it's not right to say we are a police state.
"We have very clear laws about how long suspects can be detained. Very clear laws about rules of evidence. Very clear rules about how the police must behave. And as long as the police meet all those laws then people shouldn't complain that this is somehow a police state."
Muslim Labour MP Shahid Malik said: "I can understand Abu Bakr's anger and hurt but it definitely doesn't lead to the conclusion that we're in a police state.
"It's really important that people do remain patient and let justice take its course."