Justice Secretary Jack Straw was forced to announce changes to a "get out of jail early" scheme last night after two convicted terrorists were released to ease prison overcrowding.

The Government confirmed Yassin Nassari - who was arrested at Luton Airport with blueprints for a rocket in his luggage - was freed from maximum security Wakefield Prison 17 days early, and a second man, Abdul Muneem Patel, was freed from Glen Parva jail in Leicestershire.

Opposition politicians said it was remarkable that terrorists had been eligible for the end of custody licence scheme, which was brought in last year to create more space in the overcrowded jails.

Liberal Democrat MPs accused Mr Straw of "shutting the stable door after the horse has bolted".

Nassari was freed on February 11, seven months after being given a three-and-a-half-year sentence, but had also spent more than a year on remand before conviction.

Patel was released on January 7. He had been serving six months for owning an explosives manual.

A Ministry of Justice spokeswoman said: "The number of terrorism-related cases likely to fall within the current ECL criteria is very small.

"However, in the light of these cases, the Justice Secretary has decided to change the criteria for the ECL scheme so that any prisoner convicted under terrorism legislation would not be eligible."

Blackburn MP Mr Straw said: "In the light of this case I have taken action to tackle this issue - no more prisoners convicted under terrorism legislation will be released through the ECL scheme."

Shadow home secretary David Davis said: "Jack Straw must now say when he knew about this, and why he has only just acted.

"Were these men released with or without his know-ledge? If it was without, who on earth is running his department?"

The changes come just days before a Commons vote on plans to increase the period police can question terror sus-pects to 42 days