The UK law banning smoking in public places including pubs, bars and restaurants was introduced five years ago this month, and a government-commissioned report into its effects has concluded that it has had a 'significant impact'.
England was the last part of the UK to introduce the law, following in the footsteps of Scotland, Wales and Northern Ireland in banning smoking in public.
The ban has a wide scope and prohibits smoking in train stations and office buildings, as well as airports, pubs, bars and cafes.
Amanda Sandford is the research manager at anti-smoking campaign group Action on Smoking and Health (ASH).
"When it started people wondered why we'd waited so long to do it. It is one of the most important public health acts in the last century... It's been hugely beneficial," she said.
The ban still has widespread public support, with a recent survey of some 12,000 adults suggesting that nearly 80% still approved the law. A government-commissioned review assessing the effect of the law has also concluded that it has had a significant impact.
"Results show benefits for health, changes in attitudes and behaviour and no clear adverse impact on the hospitality industry," claimed the review, lead by Professor Linda Bauld at the University of Sterling.
Studies looking at the health of workers in pubs and clubs have shown improvements in their lung function since the law was introduced and evidence from Scotland demonstrated a fall in the number of paediatric acute asthma admissions by some 15% in the three years after the ban was introduced there.
Doctors are also supportive of the impact of the legislation. Professor John Britton is the chairman of the tobacco advisory group at the Royal College of Physicians.
"The ban has had a huge impact on quality of life particularly in people with cardiovascular disease," he told the BBC.
However, some want the law to go further. Last week the House of Lords debated a private members' bill aiming to outlaw smoking in cars.