A MAN whose son was stabbed to death today joined a Labour campaign for mandatory custodial sentences for knife crimes...

A MAN whose son was stabbed to death today joined a Labour campaign for mandatory custodial sentences for knife crimes.

Scots Labour leader Iain Gray took the campaign to Greenock in the latest round of a summer sweep around supermarkets in Scotland.

Along with local MSP Duncan McNeil and John Muir, who has been campaigning for action since his son Damian was killed in Greenock in 2007, Mr Gray will urge shoppers to sign a petition.

Mr Gray said: "This is where it all began and the people of Inverclyde are to be congratulated for the support they gave to John Muir, who lost his son to knife crime.

"The SNP government and Justice Minister Kenny MacAskill have not done enough with their complacent, soft-touch approach.

"That is why Labour is calling for mandatory sentences for anyone caught using or carrying a knife."

Mr Muir has been campaigning for Damian's Law, which proposes a mandatory custodial sentence for carrying a knife or other dangerous weapon in public, to be introduced and is calling on the public to sign an online petition.

More than 8000 people have already put their names to it, and it has been supported by Inverclyde Council.

Mr Muir lost his son two years ago when he was stabbed to death in an unprovoked attack in his home town of Greenock.

Damian Muir, 34, was killed as he walked home from his football team's annual night out on July 14, 2007.

He was stabbed eight times - seven times in the back - as he tried to escape thug Barry Gavin.

Damian's killer, who already had a stabbing charge pending, as well as previous charges of knife possession at the time of the attack, was jailed for 15 years.

Mr Muir has campaigned for tougher sentencing and his petition led to a summit on knife crime at Holyrood.

At a conference debate on justice earlier this year, Mr Muir said: "We have become so used to violent crime. Is it any wonder criminals are laughing at our efforts to enforce current laws?

"Violent criminals are too often in and out of prison with short-term sentences on a revolving-door basis. This has to stop."