Jamie Vardy was seen preparing for England’s Battle of Britain clash with Wales at Euro 2016 with a cocktail of nicotine and caffeine.

The Footballer of the Year was pictured with the surprising mixture of stimulants en route to training here in Chantilly on Tuesday. He was carrying a tin of nicotine pouches in one hand and a can of Red Bull in the other.

While Vardy has not committed a doping offence, both stimulants are listed on the World Anti-Doping Agency monitoring list as something being considered for the banned list if used in competition.

Vardy holds the chewing tobacco as he heads out in his England training attire in Chantilly, France

The England international was seen holding chewing tobacco similar to the tin pictured right

CHEWING TOBACCO Otherwise known as snuff or snus, the chewing tobacco is powder in a pouch which is placed in the mouth, sitting underneath the top lip. Vardy appears to be holding an ultra strong, frosted white dry version called Thunder. It contains: 18 portions per can 11.7 gram can weight Each Portion - 0.65 gram Nicotine Per Portion - 27.3 mg/portion Advertisement

A Football Association spokesman stressed that Vardy was on the right side of anti-doping regulations and that the England medical staff are aware of the Leicester striker’s habits.

Indeed sources at Leicester believe Vardy has even used the pouches, which are most effective when placed against the gum, during games.

A spokesman for Vardy was unavailable for comment but former UK anti-doping chief Michele Verokken said Vardy’s use of nicotine raised interesting questions when used for performance.

‘The key question here for the anti-doping authorities is establishing, scientifically, if stimulants like nicotine are performance enhancing,’ she said.

‘It has been on the monitored list since 2012 and would only be an issue when used in competition. It would act as a stimulant by increasing the heart rate. But as things stand it is not a doping offence.’

England and Leicester striker Jamie Vardy pictured leaving the England hotel in Chantilly on Tuesday

In the past WADA has said that nicotine sanctions are discussed with increasing regularity.

In 2012 the publication of a year-long study at its laboratory in Lausanne concluded that nicotine increased ‘vigilance and cognitive function’, and reduced stress and body weight.

Vardy is thought to be a former smoker who uses them as a means of quitting. Two other members of the England squad here in France – Wayne Rooney and Jack Wilshere – have been photographed smoking in the past.

The 29-year-old is considering his future at current club Leicester, where he has been the subject of a £20m bid from Arsenal.

Vardy (centre) pictured alongside his England team-mates as they head out for a training session

Vardy and England are preparing to face Wales in a crucial Euro 2016 encounter on Thursday

Vardy (centre) pictured alongside his England team-mates Harry Kane (left) and Dele Alli (right)

VARDY'S PERFORMANCE 'COULD BE BOOSTED BY 7 PER CENT' Roger Pielke, director of the sport governance centre at the University of Colorado, says of Jamie Vardy’s combination of substances: ‘Both nicotine and caffeine are among the more well-studied performance-enhancing substances. It gives you a little energy boost. ‘There’s a study in my new book about caffeine across a range of sports and the performance enhancement is three to seven per cent, whether that’s rowing, sprinting or whatever. ‘Anyone who wakes up in the morning and has a cup of coffee or tea knows the performance-enhancing effects of caffeine. They’re perfectly legal and athletes take them, which is no surprise. 'Used together, do they give you an added boost in terms of energy? I’m not aware of any studies which have looked at the double benefit but look at Maria Sharapova with her 30 medicines — athletes are going to take everything and anything they can that might give them a benefit, regardless of whether the science is there.’ But Mark Leather, head of sports performance at Bolton Wanderers, played down the effects. He said: ‘Snus is a fad that I’ve seen used by a few players in the last two or three years. Some take it for its relaxing effect, instead of smoking, and it’s a fashionable thing to do. I don’t know why they do it and I wouldn’t advise players to, because of the risk of cancer. ‘I’d be very surprised if players used it during a game — it would be an irritant in your mouth. They might use it when they come off the pitch to relax. And players in every changing room will drink Red Bull before a game to give them a little pick-me-up, but I don’t think it would have a combination effect with the nicotine.’ Roger Pielke’s new book is The Edge: The War Against Cheating and Corruption in the Cutthroat World of Elite Sports. Advertisement

Leicester manager Claudio Ranieri has said the decision is entirely Vardy's as to where he will be playing next season.

'We want to keep him,' Ranieri told Sky Italia. 'Arsenal have said they will pay the full release clause, but he hasn't accepted yet.