The percentage of motorists caught drink-driving on UK roads rose this year, police figures show.
Officers stopped and breath-tested 88,629 drivers during a crackdown in England, Wales and Northern Ireland throughout June, the Association of Chief Police officers (Acpo) said.
Of those, 5,373 (6.06%) tested positive, refused or failed a breath test, compared to 5.6% during the same period last year.
The figures revealed that 7.40% of drivers under the age of 25 were breaking the drink-drive law when they were pulled over, while 5.67% of motorists over 25 were offenders.
Chief Constable Phil Gormley, Acpo's lead officer on roads policing, said: "It is worrying that younger drivers continue to drink and drive and we will be redoubling our efforts to address this unacceptable behaviour."
During the month long targeted drink and drug driving campaign, police also ramped up testing for drivers under the influence of drugs, conducting 30% more field impairment tests than in 2010.
The crackdown resulted in 122 out of 337 motorists (36.20%) being arrested.
Mr Gormley added: "We have increased the number of tests we conducted to detect people driving under the influence of drugs and this is an area where we are working with Government to improve our capabilities through reformed legislation and procedures.
"We view this as an important area for casualty reduction and will continue to pursue motorists who drive whilst under the influence of drugs, endangering their fellow road users."