Police breath-tested more drivers over Christmas, and while the overall number of people over the limit has not changed, the proportion failing the test fell.

The fall in the relative failure rate included a dip among young drivers aged 20-24, the Association of Chief Police Officers (Acpo) said.

In December 2012, police in England and Wales tested 175,831 drivers, of whom 7,123 - or 4.05% - either failed the test or refused to take it.

This compared with figures for December 2011 which showed that almost exactly the same number (7,124) failed or refused the test out of 156,569 tested - a failure rate of 4.55%.

However, the 2012 figures were still above those of December 2010 where only 6,662 - or 3.91% - failed or refused out of a total of 170,552.

Acpo said it had breath-tested more than 1,000 extra drivers in the 20-24 age group in December 2012 compared to 2011. The December 2012 figures show that there were 104 fewer young drivers failing tests compared with 2011.

Acpo's roads policing head Deputy Chief Constable Suzette Davenport said: "It's good to see that yet again the majority of drivers are responsible and sensible. Our results show that by far the majority of drivers stopped did not drink or take drugs and drive.

"We made it absolutely clear to drivers before Christmas that we would be stepping up our efforts to breathalyse them. It is encouraging to see the message has got through to even more drivers than last year."

AA president Edmund King said various campaigns appeared to have had a positive effect over Christmas. He added: "Even though there was a reduction in the number of under-25s testing positive, the proportion of positive tests (5.27%) was higher than for the over-25s (3.39%).

"Police tactics in conducting breath tests do vary considerably when it comes to drink-driving.

"The North Wales force, which represents a population of 675,000 people, tested more than 18,000 drivers. In comparison, the South Wales force, which represents 1.2 million people, only tested 3,703."

Road Safety Minister Stephen Hammond said: "Drinking and driving is incredibly dangerous and drivers should be in no doubt that if they get behind the wheel after drinking they risk losing their licence, as well as facing a fine and even a prison sentence.

"In addition, to help make it easier for the police to tackle the problem and protect law abiding road users, we want to streamline enforcement and tighten the law so that drink-drivers will have nowhere to hide."