A GRIEVING mother has launched a campaign to change the law after her son was murdered.

Barbara Dunne, whose son Robert was murdered with a samurai sword in January, has drawn up a petition backing plans for life sentences to mean life.

The Middlesbrough mother, who is caring for her one-year-old grandson, Liam, also wants the law changed so it is illegal to sell swords.

She also volunteered her services to a Middlesbrough Council-backed group working against anti-social behaviour on the Whinney Banks Estate, where she lives.

She plans to take her petition, already published on a website dedicated to her 31-year-old son's memory, to Downing Street.

Mr Dunne, 31, a scaffolder, was murdered yards from his home in the West Lane Estate, in Middlesbrough. He had been involved with disputes with an unruly gang on the estate.

Jason Kelly, 19, pleaded guilty to murder at Teesside Crown Court in July and received a life sentence, with a recommendation he serve eight years in prison.

Mrs Dunne said she backed Home Secretary David Blunkett's proposals for convicted murderers to spend more time in jail.

Revelations that a market trader was selling swords on Stockton High Street has caused Mrs Dunne to campaign for the law to be tightened.

The trader has been banned in Stockton, but Mrs Dunne said she believed the law should apply nationally.

She said: "I cannot bear the thought of the person who killed my son being free in a few years. He will still be a young man, but my Robert has gone forever and Liam has lost his dad."

David Hines, of the North of England Victims' Association, who sits on a crime committee with Mr Blunkett, backed Mrs Dunne's call for tougher sentences.

The Home Office said there were no plans to change the law on selling weapons.