The boss of Wetherspoon, one of Britain's biggest pub chains, has said Scotland could thrive on its own, and the company is forging ahead with expansion plans north of the border.

Tim Martin, who founded the chain in 1979, said: "There is no rational reason why Scotland shouldn't be able to thrive as an independent country if it has a sensible economic policy. There are lots of countries around the world with a similar population to Scotland that have done so. It will depend entirely on the will of the Scots. They have to work hard."

He held up New Zealand and Singapore as examples of small countries that have done well.

Wetherspoon is Scotland's largest managed pub chain with 75 outlets, employing 4,000 people. A managed pub has to buy some of its beer from a particular brewery or its parent company in contrast to free houses, which are independent watering holes.

Wetherspoon has opened six new pubs in Scotland in the last four months and Martin said he was aiming for about 100, employing 5,000 to 6,000 people, in five years' time, with turnover climbing to £150m from £100m.

In contrast to a growing number of retailers who have warned the higher cost of doing business in an independent Scotland would drive up prices in the shops, Martin said it was possible the price of a pint could fall.

"It's absurd and underestimates the intelligence of the public to say things like the cost of your supermarket goods is going to rise and [independence] is going to result in economic dislocation."

If the yes camp prevails, the Scottish government "might reduce VAT in pubs to the same level as in supermarkets, and they might do the same for business rates to encourage cafes and pubs. It might bring down the cost of a pint in a pub or restaurant," he said.

He said he had not yet spoken to Scotland's first minister, Alex Samond: "If they do get independence, he will be hearing from me within 24 hours," he added, with a chuckle.

Martin highlighted the VAT disparity between supermarkets and pubs as the biggest danger to the pub industry in the UK.

His comments came as a new YouGov poll showed that the no vote is back in the lead in Scotland.

Wetherspoon beat City forecasts with a 3.1% rise to £79.4m in full-year underlying profits and expects a "reasonable" outcome for the current year, following a pick-up in like-for-like sales to 6.3% in the past six weeks. Opening for breakfast, serving coffee and cappucino, along with a revamp of its food menus and promotions like curry clubs and "beer and a burger" bargains have drawn in punters, and Wetherspoon has grown to more than 900 pubs. Wetherspoon has also become the No 1 seller of microbrewery beers in Britain, Martin said.