The decision to strip controversial radical muslim cleric Sheikh Abu Hamza of his UK citizenship has been condemned by leading union boss Bill Morris.
Sheikh Abu Hamza praised Osama Bin Laden
The TGWU general secretary said that while he had no sympathy with Mr Hamza, in a democracy politicians should not be permitted deprive people of their nationality.
Mr Morris' comments came as legal representatives of Mr Hamza vowed to take his case to the European Court of Human Rights.
Such a move could delay his removal from the UK by up to 10 years.
Mr Blunkett personally signed the papers that stripped Mr Hamza of his citizenship which were then delivered to the cleric on Friday.
Parliament voted for this to make holding our citizenship worth something
Home Secretary David Blunkett
"I want to deal with people who our intelligence and security people believe are a risk to us," he added.
"If you encourage, support, advise, help people to take up training, if you facilitate them, then, of course, that takes you right over the boundary."
The move follows the introduction of new powers earlier this week allowing British nationality to be removed from people with dual citizenship who are believed to have acted against the vital interests of the UK.
Tabloid newspapers and a number of MPs have pressed for Mr Hamza's removal from the country as he has angered many with praise for Osama Bin Laden and condemnation of Britain, the US and Israel.
Egyptian-born Mr Hamza has been resident in the UK since 1979, gaining British citizenship back in 1981.
A former Soho nightclub bouncer, Mr Hamza has become the controversial face of radical Islam in the UK.
He was a regular preacher at the Finsbury Park mosque in North London until his suspension by the Charity Commission last April.
His lawyer, Maddrassar Arani, said stripping him of British citizenship would leave him stateless and would therefore be a breach of his human rights.
Ms Arani told World at One: "Sheikh Abu Hamza doesn't have dual
nationality. He can't be rendered stateless. If they do that, they will be in
breach of the (Nationality, Immigration and Asylum) Act itself."
On Sunday Mr Morris told BBC Radio 4's the World this weekend: "We don't live in an authoritarian state where the politicians can determine
overnight that somebody's citizenship should be taken away."
He added that if someone had committed an offence then it was for the courts system to decide the appropriate punishment.
"What worries me is that the politicians are making the law and executing the
law and when the politicians start passing the sentence, that's when our freedom
"Taking a person's nationality away is probably the most draconian measure,
and it seems to me that politicians should not be in charge of that
In 1999 Abu Hamza was questioned by Scotland Yard detectives on suspicion of terrorism offences in Yemen.
He was held for several days before being released without charge. He has always maintained his innocence.
The Yemeni authorities had requested his arrest and extradition, claiming he was linked to plots to bomb targets there.
But Mr Hamza came to real public prominence in the aftermath of September 11 when he praised the terrorist attacks on the US.
Home Office lawyers believe Mr Hamza's Egyptian nationality has never been revoked.
As a result under section four of the Asylum, Immigration and Nationality Act 2002 the radical cleric could be stripped of his citizenship.
Until a Deprivation Order is upheld, Mr Hamza will remain a British citizen and will not be able to claim asylum in the UK.
This will be the first test case under the new powers.