Sir Richard Branson has weighed into the referendum debate, saying it is "imperative" Scotland remains part of the Union.

The Virgin chief, whose wife is from Glasgow, said he would "love" to see Scotland stay part of the UK.

He said: "As a businessman, considering Scotland's economy, prosperity and security, I think it is imperative it stays in the Union. It is clear that the people of Scotland want change. And whatever the outcome of the referendum, change is on the cards.

"If the vote stays as close as the polls suggest, there won't be a mandate to separate, or to keep the Union exactly as it is. Keeping the status quo is no longer an option and the Scottish Parliament needs greater powers."

Sir Richard's intervention follows a number of major employers speaking out in favour of Scotland staying in the UK.

It also follows on from a series of Scottish banks, including Lloyds, RBS, Clydesdale Bank and Tesco Bank, confirming plans to relocate their head­quarters to England if Scotland votes to leave the UK.

Meanwhile, Yes campaigners welcomed comments from the chairman of pub group Wetherspoons, stating there is "no reason" why Scotland cannot be a "very successful independent country".

The remarks from Tim Martin come amid reports that some retail chiefs plan to publish a joint letter warning of price increases in their stores if the country votes Yes in next week's referendum.

Speaking to the BBC, and asked how independence would affect his company, Mr Martin said it is "difficult to say".

He continued: "There's no reason in theory why Scotland couldn't be a very successful independent country.

"New Zealand has got the same population, does very well, Singapore, a smaller population, incredibly successful economy, Switzerland does well.

"There is a lot of nonsense talked, particularly by businessmen, also politicians, to say that it is impossible for Scotland to survive as successfully by itself."

Asked if, for example, the cost of a pint would go up under ­independence, he added: "Absolutely no sensible reason in the world. England has the highest taxation of almost any country in the world for alcohol duties, very high VAT... so no reason."

Wetherspoons has 70 branches in Scotland, with sales exceeding £100 million.

Scottish Finance Secretary John Swinney said: "Tim Martin's comments today are very welcome - confirming the strong business confidence in Scotland and showing the ­desperate Tory-inspired scaremongering of the No campaign isn't working.

"Tim Martin is absolutely right to say that the increasingly desperate claims of the establishment over the last few days are 'a lot of nonsense'.

"The No campaign has resorted to shameful attempts to talk down the Scottish economy - but this scaremongering is backfiring spectacularly as David Cameron's role is uncovered.

Better Together campaign director Blair McDougall said: "We welcome this announcement from Sir Richard Branson. He may not have a vote in the referendum, but he has a voice, and he is using it to say that Scotland's future is brighter as part of the UK. It is significant that the UK's most recognisable business leader has looked at separation and decided it's a bad deal.

Business Secretary Vince Cable has said he directly encouraged two leading retailers to publicly express their concerns over independence.

His advice came in a recent meeting with senior figures from both John Lewis and Sainsbury's, he told LBC radio.

Warnings of higher prices for shoppers in an independent ­Scotland have been dismissed as Westminster-led scaremongering by the Yes camp.

But Mr Cable said the "overwhelming bulk of businesses" considered a Yes vote a potential disaster and it was right they should speak out.