Party-goers are being warned to think before they drive in the morning after a big night out during the festive season.

That’s the key message during this year’s month-long police drink and drug-driving campaign, which starts tomorrow.

The crackdown follows last year’s campaign, which saw more than 4,435 drivers breathalysed by Thames Valley Police between December 1 and December 31, 2009. Of those, 257 drivers (less than six per cent of those tested) provided positive results.

Nationally, during the campaign 223,423 drivers were tested, resulting in more than 7,500 arrests.

Insp Colin Clark, who is leading the operation, said: “Many people think they have to be involved in a collision or commit an offence to be stopped and breathalysed.

"However, police officers can stop any vehicle at any time, day or night. They do not have to have a reason.

“We will be targeting all drivers suspected of drink-driving or being influenced by drugs. This will be carried out by holding dedicated road checks; testing all drivers involved in collisions and testing anyone who has committed an offence or is suspected of drug-driving.

“We will also be acting upon information from the public, targeting those areas or drivers where there is a problem.

"More officers are now trained to test for drug use at the roadside, so we are well equipped to deal with all drivers that come our way.

“The high-profile road checks are being run to raise the awareness of Operation Tipple, making sure drivers and their passengers understand that we are dealing with this offence robustly.”

Supt Rob Povey, head of roads policing in the Thames Valley, said: “We are asking the public to be safe rather than sorry.

"Collisions involving alcohol or drugs not only devastate the lives of victims and their families, they also ruin the lives of offenders, who could face a lengthy driving ban or imprisonment.

"As well as having to live with the lifelong guilt of having killed or injured someone through their reckless behaviour, offenders could also lose their job, home and their livelihood.

“If you are going out and know you will be drinking, organise alternative transport or a designated driver to ensure everyone is able to enjoy the festive period safely.”

The Christmas campaign runs from December 1, 2010, to January 1, 2011.

All drivers who provided positive breath tests, refused to provide or failed to provide, face losing their licence for at least 12 months. They could go to prison for six months or pay a fine of up to £5,000.

In last year's Christmas campaign, police carried out 1,321 tests in Oxfordshire, of which 75 were positive.