Planning red tape means licensees could wave goodbye to their smoking regulars on July 1 as outdoor areas fail to materialise.
Many pubs are expected to start the first days of the ban with no external areas while they wait for planning authorities to process their applications, which can take up to 12 weeks.
Concerns have also been raised about the inconsistent interpretation of the regulations and authorities' failure to acknowledge planning applications from operators, leaving them in the lurch.
With less than two weeks until the ban, Mike Rawley, of the Gannow Wharf in Burnley, Lancashire, has been told the marquee in his garden is illegal even though it is 50 per cent open as indicated in the regulations.
He said: "It's like banging your head against a brick wall. I've asked the council to come out to have a look at it. If someone comes out they'll see it's so open, it's unreal."
Licensee Tim Willis, of the White Horse Inn in Washford, West Somerset, is having his application for a portable shelter examined by the Planning Inspectorate, the government planning regulator.
Willis said: "I just want to throttle someone, to be honest with you. I'm not a smoker myself, so I have not done it for my own personal use, it's for when the ban comes in."
Chris Howard, director of Leeds-based N8 Leisure, was refused planning permission to erect a 30ft-long canopy above the riverside terrace of Aire Bar because it is a listed building. He has paid out £7,000 in legal costs and is now providing smokers with branded umbrellas.
He said: "It's so frustrating for us to have started this process more than two years ago and it looks from a customer's point of view as though we have left it until the last minute."
Punch Taverns, which owns 8,400 pubs, warned that the timescale may lengthen due to the surge of planning applications before July 1.
Neil Martin, legal director for Punch Taverns, said: "The most time-consuming part of the process is understanding the ways in which different councils are interpreting the guidelines before we draw up planning applications. We want to ensure that any structures where smoking will be permitted not only receive planning consent, but also comply with the smoking ban."
A spokeswoman for local authority co-ordinating body LACORS said: "We have been encouraging councils to work with businesses to ensure they are aware of their responsibilities in relation to the legislation and in particular with regards to licensing and planning, if they intend to provide outside smoking areas."