The father of a man who was stabbed to death today called on MSPs to back mandatory jail terms for carrying a knife.

John Muir, whose son Damian, 34, was killed in a knife attack in Green­ock three years ago, has become a high-profile campaigner and was giving evidence to Holyrood’s Justice Committee today.

MSPs are considering a Labour amendment to the Criminal Justice and Licensing Bill which would result in six-month sentences for anyone carrying a knife, other than in exceptional cases.

The committee will also hear from Chief Constable David Strang, from the Association of Chief Police Officers in Scotland, on the issue.

Moves to tighten the laws on prostitution will also come under the spotlight of the committee.

Labour’s Trish Godman wants new offences introduced which would mean prostitution could not take place without an offence being committed by the customer.

Nationalist committee member Nigel Don is also calling for a new offence of paying for sexual ­services of a prostitute subjected to force.

Campaigners and police chiefs will also give evidence on Labour moves to create new offences of stalking.

The Government wants to see the introduction of a wider offence of threatening, alarming or distressing behaviour.