UP to 30 “high-risk” terrorists — including some of the most dangerous men in Britain — are due to be released from jail in the next year.

More are being freed in the wake of a ruling by Britain’s most senior judges that long sentences for terrorist crimes could “inflame” rather than deter extremism.

An analysis of appeal court cases shows that of the 26 terrorism cases it has heard, 25 have led to men with terrorism convictions having their sentences reduced.

Others are being released because they serve only part of their term. In response, Chris Grayling, the shadow home secretary, said the Tories were considering longer sentences for terrorists.

The leniency of the British appeal court to some convicted terrorists contrasts with America where they can be locked up for their whole lives.One man designated “high risk” and due to be freed soon is Andrew Rowe, a Muslim convert who was found guilty of having notes on how to fire mortar bombs.

Rowe was sentenced to 15 years in 2005. He is due to be freed next April after his sentence was reduced to 10 years. Others who have had their sentences cut include some of those who helped the failed suicide bombers of July 21, 2005 and two of those convicted of soliciting murder during the Danish cartoons protest.

The sentences were reduced after a key ruling in July 2008 by Lord Phillips, then the lord chief justice, and two other senior judges, who reduced Abdul Rahman’s sentence from six to 5½ years following his guilty plea for disseminating a terrorist publication.

Rahman, a key Al-Qaeda player, recruited disaffected Muslims from northern England to fight British troops in Afghanistan.

The judges stated: “Care has to be taken to ensure that the sentence was not disproportionate to the facts of the particular offences. If sentences were imposed which were more severe than the circumstances of the particular case warranted, that would be likely to inflame rather than deter extremism.” This was the green light for further sentence reductions in subsequent terrorist appeals.

Harry Fletcher, of the probation service union Napo, said: “Due to the extraordinary number of successful appeals, scores more terrorists will be released. Every single one that comes out will have to be supervised until their full sentence expires.”

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