Patrick Martin, 37, from Tooting in south London, was jailed for 35 years in July 1997.

But on Wednesday his sentence was reduced to 28 years after the Court of Appeal decided to make allowance for the fact that "death and injury was not the primary object" of the campaign.

Patrick Martin...sentence cut

Martin was one of six members of a Provisional IRA "active service unit" who were described by the trial judge, Mr Justice Scott Baker, as bent on "destabilising the community by wrecking electricity supplies to the south east of England".

In June 1996 Martin's gang plotted to blackout the whole of London by targeting key electricity sub-stations.

Thwarted by police

The campaign was thwarted by an undercover police and MI5 operation.

Jailing them the judge said: "You were reckless as to the number of people who might be killed or maimed as a consequence of your planned bombings."

But the Lord Chief Justice, Lord Bingham, sitting with two other judges, said: "The political, economic and social threat presented by this conspiracy was as great as in any of the cases we have considered."

He added: "We do, however, conclude that some weight must be given to the fact that death and injury, although a likely by-product of implementation of the conspirators' plan, was not its primary object."

Lord Bingham said 35 years was the sort of sentence handed out to multiple murderers.