Northern Ireland has gone smoke free from today but many licensees have been forced to put up illegal smoke shelters because of planning delays.
Federation of the Retail Licensed Trade said pubs and clubs had no choice because having no facilities for smokers would be commercial suicide.
This is a major risk for many publicans, but they have to provide facilities for their customers who smoke or they may as well close their doors forever Federation of the Retail Licensed Trade Nicola Carruthers.
Federation spokesman Nicola Carruthers said: "With the planning system experiencing massive delays, of up to 18 months in some parts, many businesses are building beer gardens and smoking shelters without planning permission and applying retrospectively.
"This is a major risk for many publicans, but they have to provide facilities for their customers who smoke or they may as well close their doors forever."
It is now illegal to smoke in pubs, clubs, workplaces and most enclosed public spaces and on public transport in Northern Ireland.
The ban will be enforced by local councils and a 'shop a smoker' hotline has been set up so people can report breaches of the ban.
Northern Ireland's health minister Paul Goggins said the law would save lives, adding: "People do not want to breathe in others' smoke."
Brian Gaffney, chair of the Smoke-Free Northern Ireland coalition and chief executive of the Health Promotion Agency, said: "This is one of the most important public health initiatives in Northern Ireland since the health service was established and it should be celebrated."