An undercover operation will be mounted in west Oxfordshire this year to check licensees are not serving alcohol to children.

Underage drinkers will be sent into pubs, bars and shops to test the response of staff during the joint exercise between Thames Valley Police and West Oxfordshire District Council.

The operation is expected to take place three or four times between now and December, and comes after the success of a similar operation in Oxford.

Bill Oddy, head of community safety and licensing at the council, said: "Licensees in west Oxfordshire have considerable experience and we don't believe there is a significant problem. We are more than happy to advise and support licensees who want to review their procedure."

Insp Andy Higgs, of Thames Valley Police, who has responsibility for licensing, said: "We have now implemented neighbourhood management policing across the district and one of the emerging problems for the public is young people and alcohol."

Nearly 400 licence holders in west Oxfordshire have been warned the operations will be taking place at random, to give them the chance to tighten up procedures for checking a customer's age. A similar scheme in Oxford was hailed a success after bars and pubs cleaned up their act and got strict with underage drinkers.

Last month, Operation Breezer saw staff in seven city centre bars refuse to serve a pair of 15-year-old girls, who had been sent in by police and council officers.

That was a marked improvement on an earlier test in February, when the underage drinkers were served in four out of seven bars selected.

Chris Proudfoot, owner of The Old School in Oxford, one of the pubs which was fined during the first crackdown, said at the time: "We have been doing a lot of staff training and making sure everyone checks no matter what."

Karen Crossan, manager of Nightsafe, the scheme to combat Oxford's drug and alcohol-related problems, said: "I am sure that the previous operation sent out a warning that serving underage drinkers will not be tolerated in Oxford city centre."