A flagship Government policy to stamp out underage drinking was labelled a failure after being virtually ignored by police.

Ministers last year announced new powers for police to give on-the-spot fines to under-18s who try to buy alcohol, along with bar staff and shopkeepers who serve them.

Government figures reveal Thames Valley Police issued an average of just one on-the-spot fine for those offences every two months.

A total of six fixed penalty notices were handed out in the Thames Valley for the new offences, between November 2004 and September last year.

Figures for Oxfordshire were not available. Nationally, 1,316 have been handed out.

The revelation comes after staff at four Oxford bars became the first in the city to be fined £80 for serving schoolgirls in an undercover drinking operation last month.

And police in Oxford said they now want bar managers to invite them to carry out covert operations to catch underage drinkers.

Insp Graham Sutherland, of Oxford police, said: "What MPs are talking about is the flip-side of what we were doing.

"We were targeting licensees who serve under-18s. This is focusing on under-age people who try to buy alcohol. To tackle this we would need to undertake covert operations.

"We would be reliant on bar staff to come to us and say they have regular problems with under-age drinking, then we could work together to do something about it."

He said plain clothes officers could go into the pubs, to hand out penalties to underage drinkers.

He said if bar staff invited officers in, they would not be fined for serving youngsters.

Shadow Home Secretary David Davis said: "Yet again a Government policy, while proving effective at gathering the headlines, has utterly failed to address the problem.

"Violent crime -- much of it fuelled by drink -- continues to increase on our streets."

A Home Office spokesman said: "For the first 10 months of the Penalty Notice for Disorder scheme there were nearly 1,000 issued against individuals found to be selling alcohol to people under 18 and more than 100 given to people who allowed under-age drinkers to buy alcohol on licensed premises.

"This shows that using the new scheme police are clamping down on those willing to break the law and serve or sell alcohol to under-18s."