Trade leaders were called in front of the Greater London Authority (GLA) thisweek to argue their case against a ban on smoking in pubs.
The authority's decision on the matter is likely to affect smoking policy in key areas across the UK.
The GLA has been considering a ban since early this year and is currently hearing evidence from the trade and other interested parties before making a final decision.
The Association of Licensed Multiple Retailers (ALMR) and the British Institute of Innkeeping (BII), which have been arguing for self-regulation via a voluntary charter agreed in 1998, presented evidence of the effect the charter had already had in pubs.
The evidence included research among pub-goers and barstaff in London which showed they believed the trade was winning its battle against smoky atmospheres.
The survey, carried out in eight recently upgraded pubs, revealed 85 per cent of customers rated the pubs' air quality as "comfortable" or "very comfortable". Fifty-eight per cent said the air quality was "less smoky" or "much less smoky" than that of other venues.
Georgina Wald of the BII said: "This survey strongly backs up our belief in self-regulation on the issue. Customers and staff are happy with the conditions, and with about a thousand premises being upgraded nationally this year the industry is well on top of the issue."
Nick Bish, chairman of the trade's Charter Group and chief executive of the ALMR, pointed out that 39 per cent of customers thought that ventilation of this quality was the best option for licensees to adopt, with 35 per cent opting for designated no-smoking areas.
Mr Bish said: "Recent research apparently backing a ban in public places is based on old ideas of what pubs are like. Only 13 per cent of consumers in these outlets thought this was a good idea. The industry has changed and is changing fast.
"There are pubs equipped to this standard in most towns and they are easy to spot with their distinctive charter signs. Operators are investing heavily to make these standards available in every High Street."
The research was carried out in pubs owned by Brodie City, Fuller, Smith and Turner, Glendola Leisure, Old Monk Pub Company and Six Continents Retail.