Prince Harry, the third in line for the British throne, has vowed to quit smoking in the New Year ahead of a sweeping army ban.

The 22-year-old prince first took up cigarettes at the age of 14 while he was still a pupil at Eton, often cadging them from older boys at the exclusive public school, The Daily Mail reported on Tuesday.

He has carried on smoking up to twenty Marlboro Lights a day ever since, even through his grueling yearlong army training course at Sandhurst, the report said.

Cadets at the Royal Military Academy are not allowed to smoke inside the college but are permitted to do so in their free time.

Though officer Harry earlier insisted that his habit did not interfere with his health or fitness, he has finally made a New Year's resolution to give it up for good.

His decision comes as the Ministry of Defence prepares to ban smoking at all army barracks from March and army sources have suggested that Harry wants to cut down gradually before the new regulations come in.

His decision is likely to hearten his father, Prince Charles, who loathes his son's nicotine habit. His wife, the Duchess of Cornwall, was herself a heavy smoker but is believed to have given it up in recent years.

Unfortunately for Harry, his girlfriend Chelsy Davy is a social smoker, which is unlikely to make kicking the habit any easier for him.

"Harry tries not to be seen smoking in public but behind closed door and at parties he's always lighting up," a royal source told the tabloid.

"His father nags him constantly about it but Harry has never shown an inclination to listen to him until now."

Harry is currently enjoying a nine-day holiday in Mozambique with girlfriend Chelsy and her family courtesy of her controversial multi-millionaire father, Charles.

The couple heralded in the New Year by partying until dawn on the beach at Bazaruto island after enjoying a lavish seafood banquet and watching a spectacular fireworks display.

Harry returns to England on Friday to re-join his Blues and Royal regiment when he will be formally told whether he will be sent to Iraq in the spring.