The number of smokers in Britain has dropped for the third year in succession, continuing a 40-year trend which has seen numbers cut in half.
The latest data from the Office for National Statistics shows that 17.2% of adults in the UK smoked in 2015, down from 20.1% in 2010.
Smoking levels are highest in Scotland, at 19.1%, followed by Northern Ireland, at 19%, Wales on 18.1% and England on 16.9%.
The numbers have been dropping fastest in recent years in Scotland and Wales.
Among local authorities, Blackpool is the only one to feature consistently in the 10 heaviest smoking areas between 2012 and 2015.
In 2015, 25.3% of adults in Blackpool smoked compared with 8.8% of adults who smoked in the Chiltern area of Bucks and 9% of adults who smoked in South Staffordshire.
It comes after some groups called for greater controls on smoking due to the cost of healthcare.
Half of the 2.3 million who were current users of e-cigarettes at the time of the survey said they were doing it to quit smoking.
A further 22% said they were vaping because it was less harmful than smoking. Only 10% said they chose to vape because it was cheaper than buying cigarettes.
The figures will bolster the arguments of those who believe e-cigarettes have a major role to play in ending the tobacco epidemic.
The issue has been hugely controversial among public health doctors and campaigners, some of whom consider e-cigarettes to be a stalking horse for the tobacco industry which hopes to make smoking acceptable again and has invested in vaping.
Meanwhile the use of e-cigarettes which has been seen as a healthier alternative to the traditional cigarette in recent years, saw a modest rise in use of just over one per cent to 4.5%.
The study also found that smoking is more common among those earning less than £10,000 per year in addition to those who are currently looking for work.
Deborah Arnott, chief executive of health charity ASH said: "The fact that smoking has declined among young people has occurred while e-cigarette use has increased rapidly among smokers suggests that there is little merit in the 'gateway theory', ie that e-cigarette use encourages smoking.
"It is also a testament to the strong tobacco control measures that have been in place for a number of years in the UK which include the ban on smoking in public places, sustained increases in the price of cigarettes, heavy restrictions on marketing and mass media campaigns designed to discourage smoking.
"However, despite the encouraging trends we are concerned that it is now over a year since the last government strategy expired and funding for tobacco control is being cut. There is good evidence globally that without government leadership and a properly funded strategy smoking rates could start to rise again."