BREWING giant Tennent's has put its weight behind a grieving mother's campaign to force new licensing legislation aimed at improving the safety of young drinkers.

Donna O'Halloran, 41, has suffered a "hell on earth" since the night her student son, David, 18, disappeared on his way home from a bar and inexplicably walked off to his death.

At the time, police said the teenager was drunk and suffered hypothermia, but his mother always maintained her son's drinks were spiked, causing a disorientated state.

David, who was studying maths and education at Stirling University, went missing in the early hours of January 18.

The results of a toxicology examination last month bolstered her belief someone was to blame for the tragedy, showing high levels of the date-rape drug GHB in her son's system.

Ms O'Halloran, from Kilmaurs, Ayrshire, is heading to Holyrood to push for new laws for bars and clubs, including the introduction of compulsory hi-tech coasters that can show if drinks have been spiked.

Her campaign has been given a major boost after Tennent Caledonian Breweries gave its backing to her proposals.

Executives at the Glasgow beer giant met Ms O'Halloran a few days ago and offered support. They also plan to give her drug-testing beer mats and have offered her assistance to "ensure her campaign is heard" at Parliament.

John Gilligan, managing director of Tennent Caledonian Breweries, said: "We are keen to ensure the evening economy is as safe as possible for people to enjoy themselves."

Ms O'Halloran has the support also of Willie Coffey, MSP for Kilmarnock and Irvine Valley.