The widow of a headteacher stabbed to death outside his London school said she was "devastated" at a ruling that his killer would not be deported.

Frances Lawrence said she was "unutterably depressed" that the human rights of her husband Philip's murderer were deemed more important than those of her family.

Mr Lawrence was killed outside St George's Roman Catholic School in Maida Vale, west London, as he protected a 13-year-old pupil during a gang fight in 1995.

Learco Chindamo, who was 15 at the time, was sentenced to an indefinite term for the murder and ordered to serve a minimum of 12 years.

Chindamo, now 26, was born in Italy and came to Britain at the age of five.

However, yesterday the Asylum and Immigration Tribunal decided that he should be allowed to stay in Britain after his release.

His lawyers argued that deportation back to Italy would breach his human rights, as he spoke only English and had no family ties on the continent.

Mrs Lawrence, who was left to raise the couple's four children alone, said: "I'm unutterably depressed that the Human Rights Act has failed to encompass the rights of my family to lead a safe, secure and happy life.

"I feel that I have always been a staunch advocate of the Human Rights Act but there is a missing term in it. It must encompass some responsibility.

"This isn't just about me and my family. I am not solely thinking of me. I may be a mother but I am a human being as well.

"I feel I can't fight any more. I feel I can't survive this."

The Home Office confirmed it would be appealing against the ruling.

"We think, given the nature of this crime, actually the individual has forfeited his right to remain in the UK," said Home Office minister Tony McNulty.

Chindamo, whose mother is Filipino, led 12 youths of the Wo-Sing-Wo gang as they attacked a boy who quarrelled with a Filipino pupil.

When Mr Lawrence intervened, he was punched and stabbed. He died the same evening.

Yet Chindamo has always claimed the killer was another youth wearing his jacket, while he stood 30 feet from the murder scene.

Alan Gordon, vice-chairman of the Police Federation of England and Wales, said the decision not to allow his deportation was "ludicrous" and "absolute madness".

He went on: "The fact that he may be paroled and back on our the streets as early as next year is in itself disgusting. Life should mean life.

"What about the human rights of Philip Lawrence, robbed of his life by a thoughtless knife attack, or the human rights of Mr Lawrence's wife and children, deprived of a loving husband and father?"

But Chindamo's solicitor Nigel Leskin said he was a reformed character unlikely to offend again.

"He was involved in a gang when he was young. He was a kid trying to act up big. He was out of control and he thought he knew everything. He now realises how wrong he was.

"He strikes me as a very reformed, very nice, very thoughtful person."