A weekly paper has won high praise for its successful drug driving campaign in an exclusive interview with the Prime Minister David Cameron.

The Croydon Advertiser spearheaded a drive to introduce tougher new laws for drug drivers, launched in 2010 after 14-year-old Lillian Grove was knocked over outside her home by a driver who had taken cannabis.

Her killer, John Page, was given just eight months in prison.

In an exclusive interview with the Advertiser, David Cameron said the campaign had sent a “clear message” that legislation needed to change, and paid tribute to the tragic teenager’s family.

“The role they played was really important,” he told the paper.

“They had suffered terribly but they had a very clear message, a very strong campaign, a very supportive local MP and the case they put, I thought, was impossible to answer.”

The front page of the Croydon Advertiser at the launch of the Lillian's Law campaign in 2011

It comes as the government announced earlier this month that it intended to adopt a ‘zero tolerance’ approach to eight illegal substances covered by the new law, designed to mirror the stance on drink driving.

Led by reporter Gareth Davies who worked with Lillian’s family, the campaign was backed by more than 20,000 people, road safety charities and Croydon Central MP Gavin Barwell, and was taken up by the Premier when the family met with him at Downing Street.

After being included in the Queen’s Speech last year, the new offence of drug driving was included in the Crime and Courts Act 2013, which achieved Royal Assent in April.