Vapers are slightly more likely than smokers to do this (37 per cent compared to 31 per cent), but despite 57 per cent feeling guilty, they admit they simply cannot help themselves.
However, 18 per cent have been fined after being spotted – and although 32 per cent felt anxious when doing it, 23 per cent got "a sense of thrill".
While in London, where 20 per cent of smokers regularly break the rules, 66 per cent report feeling guilty about their illicit habit, with hotel rooms and public toilets emerging as the capital's top spots.
And Northern Ireland appears to harbour the most conflicted nicotine users, with 70 per cent feeling guilty about smoking where they shouldn't but being unable to help themselves - while Yorkshire shows the least remorse at just 39 per cent.
There was also a notably higher rate of workplace smoking in Wales, where 34 per cent admitted to breaking the rules - significantly higher than the West Midlands' 23 per cent.
