The successful appeal of nine men who hijacked a plane with 150 passengers on board sends out a dangerous message, the Tories have claimed.
The plane was diverted to Stansted
Shadow transport secretary Tim Collins said the ruling may lead to the UK being seen as a "soft touch" for hijackers.
And the general secretary of the British Air Line Pilots Association said the judgement was "amazing".
During a three-day siege at Stansted Airport in February 2000, the nine Afghan men had threatened to murder passengers and crew.
They were jailed at the Old Bailey in 2001 for hijacking an Afghan Ariana Boeing 727 on an internal flight in Afghanistan.
But on Thursday the convictions were ruled "unsafe" after three judges heard argument
that the law relating to whether they acted under "duress" because of their
fear of the Taleban regime had been wrongly applied at their trial.
The leaders of the hijack, brothers Ali and Mohammed Safi, who were jailed for five years, remain in jail.
Is it right that someone escaping fear of death then puts the lives of others at risk?
British Air Line Pilots Association
The seven others were jailed for between 27 and 30 months and have already served
Mr Collins told BBC Radio 4's Today programme: "I think it is the responsibility of all of us in authority in the UK,
whether in Parliament, or the judiciary, or anyone else, to send out a signal
that there is no justification, no excuse and no defence for acts of
"My concern is that this may be sending out a signal that somehow Britain has
become a soft touch on hijacking, which, of course, would put both UK airlines
and UK airports at risk.
"There is always cause behind the actions that people take and very often
that cause is not necessarily an illegitimate one, but that does not justify
putting people's lives at risk."
Solicitor Imran Khan said the men wanted people to know that they had hijacked the plane "out of necessity" to escape the Taleban regime.
He said: "There has been much made of the fact that they wanted to escape for
unconnected reasons and they want to make it clear that it was either escaping
by hijacking or lose their lives by the Taleban - and that position has been
But Jim McAuslen, general secretary of the British Air Line Pilots Association, told Today that the judgement should have been a question of "safety, not morals".
He said: "Clearly we have nothing but sympathy for the people living in Afghanistan at this time, but is it right that someone escaping fear of death then puts the lives of others at risk?
"For us it is not an issue of morals it is an issue of safety.
"It's amazing that the UK puts a huge effort, quite rightly, into ensuring that aviation is safe and then we have a judgement like this that apparently gives a green light to hijackers to come along and hijack planes with impunity."
The Crown Prosecution Service says it is to appeal against the ruling.
A spokesman for Essex Police spokesman said: "There was never any doubt that the men responsible had forcibly taken the plane, the crew and the passengers and
flown them halfway around the world under threat, and using firearms, explosives
"The Court of Appeal has now determined that they are not guilty of a
The Home Office said asylum applications by the nine men were still being assessed.
A spokesman said the court ruling did not mean they now had the right to stay in the UK.
He said: "In general terms, due to the considerable improvement in
conditions in Afghanistan, it is now possible to remove failed asylum seekers
back to the country. This process began at the end of April.
"Before the court case the individuals' claims were being dealt with and they
have not yet been finalised."
He said the men had no automatic right to compensation but that any application would be considered by the home secretary under the Criminal Justice Act 1988.
There have been estimates that the total cost of the legal process for the men amounted to £20m.