A pub chain has been accused of putting "profits before sense" after opening a new outlet at a motorway service station.
The move sends motorists "all the wrong signals", an alcohol charity has warned.
Alcohol Concern said the new JD Wetherspoon pub on the M40 was a "backwards step".
The Hope And Champion will be open from 4am to 1am, seven days a week, in the Extra Motorway Service Area at junction 2 of the M40 in Beaconsfield, Buckinghamshire.
The company has spent more than £1.1 million on the pub - the first to be opened at a motorway service area - which will sell real ale from local and regional brewers as well as non-alcoholic and hot drinks.
Eric Appleby, chief executive of Alcohol Concern, said: "Selling alcohol on our motorways sends all the wrong signals to drivers, it just sounds like profits being put before sense.
"Campaigners have worked tirelessly to improve road safety in the UK and persuade people that drinking and driving don't mix and this feels like a backward step."
Sir Ian Gilmore, special adviser on alcohol at the Royal College of Physicians and chair of the Alcohol Health Alliance, said motorway service stations are supposed to be "havens" for tired and stressed drivers. He said that people will succumb to temptation if they see alcohol in front of them.
"I know people can drive off the motorway to find a pub but they make an active choice to do that," he added.
"I think it is madness. It has the potential to undo all the good that has been done in drink-driving campaigns.
"This sends out the wrong message at a time when drink drinking deaths were up last year."
Steve Baldwin, manager of the new pub, said: "The Extra Motorway Service Area, now including The Hope and Champion, primarily serves the motorway users, but its facilities are also available to the surrounding community from the local road network."
Eddie Gershon, spokesman for JD Wetherspoon, added: " People think 'should we have a pub within a motorway network?'
"Our argument would be that it is a well-run pub and people have to act responsibility, which we think people do.
"Actually the vast majority of people coming in here will be eating and drinking non-alcoholic drinks like coffee."
But road safety campaigners said the concept was "at odds" with public opinion.
A survey of 2,000 people showed that only 12% supported putting pubs into motorway service stations, the RAC said.
"The public appear to be very much against the introduction of motorway pubs," said Pete Williams, the RAC's head of external affairs.
"We appreciate the vast majority of motorists drive responsibly and that alcohol is already available in shops at motorway services, but for many this decision seems to be at odds with common sense. In our view this is a risky and frankly unnecessary move."
Ellie Pearson, of safety campaign group Brake, said: "The opening of a pub on a motorway is deeply concerning, and presents a potentially deadly temptation to drivers.
"Drink driving remains one of the biggest killers on our road, causing devastation to families and communities every day.
"Our advice to drivers is not to have even a drop of alcohol if you are driving."