Hundreds of irresponsible motorists were caught during a police crack down on drink and drug driving.

A joint operation between Thames Valley and Hampshire Police - Operation Holly - saw 666 people arrested between the start of December and the New Year.

The majority of arrests (391) came from Thames Valley and officers saw a 28 per cent increase for people driving under the influence of drugs.

Road Safety Sergeant Rob Heard, from the Roads Policing Unit, said: “This year we have been very intelligence-led and worked closely with our partners from other organisations to help remind people of the dangers and consequences of impaired driving.

“We have seen a small drop in the number arrested for drink driving, which is good however there continues to be a steady rise in the number caught for drug driving over the last few years.

“We need to consider that the increase in drug driver arrests is not necessarily because we have more drug drivers on the road but that officers can conduct road side drug testing, using drug analysers to test for a level of certain illegal drugs in a person’s saliva, which was not available pre-2015.

"The difference being that there only needs to be a trace of one of the eight illegal drugs and no proof of impairment is required for a conviction."

Of all the arrests made in Thames Valley, Milton Keynes (63), Reading (52) and Slough (49) represented hotspots for drink and drug driving.

More than 4,200 breath tests were carried out during the campaign, with 155 people found to be over the limit.

The worst offending drink driving age group was 35-49 years, while the highest number of drug drivers were aged 17-24.

Sgt Heard added: “Different drugs will vary in the time they take to process through your system, some can still be measurable and at an illegal limit to drive some days after use depending on amount and frequency of use.

“Our message is simple – don’t mix drink or drugs with driving, they may stay longer in your system than you think – it’s not worth the risk.

"Such behaviour on our roads has far-reaching effects not just for the impaired driver, but for any innocent road users affected by their destructive decisions.

"It is disappointing that some people still take that risk. Too many people continue to be complacent about the realities of road deaths and serious injuries.

"That is why we want everyone to be clear about their responsibilities, and have respect for each other on the road.”

Call police on 101, or contact Crimestoppers anonymously on 0800 555 111, if you have any concerns.