The firm was at the centre of a storm during the Scottish independence referendum when its founder Bill Munro sent an email to most of his employees warning that a Yes vote would be a “complete disaster” for the travel industry.
He said he was determined to set out “the facts, not the lies being put out by the SNP” after being asked by many of his staff for his views about the ramifications of independence.
Among the concerns he raised were a separate Scotland’s debt levels, currency, EU membership, North Sea oil revenues, interest rates, public spending levels and the cost of leaving the UK.
At the time, Mr Munro’s email led to a hostile reaction from Nationalists who took to social media to denounce the entrepreneur who built up the company to become one of the UK’s most successful travel operations.
Almost two years after the referendum Mr Mason, who has recently been on holiday in Ireland, re-ignited the row when he tweeted: “I’m boycotting Barrhead Travel as they’re on the No side. Got euros elsewhere.”
Other twitter users pointed out that Barrhead Travel employs workers in Mr Mason’s Glasgow Shettleston constituency.
Scottish Conservative MSP Murdo Fraser said: “The only possible explanation for such a tweet is that he was joking.
“But the danger comes when an element of nationalist followers take the message seriously, and use it as an excuse to behave in an unacceptable way.
“With that in mind, perhaps Mr Mason could clarify that his remarks were made in jest.”
Glasgow MSP James Kelly said: “John Mason must have difficulty going about his daily business if he refuses to deal with those who raised concerns about independence. By his own logic he can’t do his shopping in Asda or Morrisons. He can’t fill up his car in a BP or Shell petrol station. He can’t buy any DIY products from B&Q. He can’t bank with RBS or Lloyds. He can’t go the pictures at the Parkhead Forge in his constituency to watch anything to do with Harry Potter, Judi Dench, Emma Thomson or a whole load of other entertainers. He can’t enjoy the music of Rod Stewart, David Bowie or Susan Boyle. He can’t even eat a Tunnock’s tea cake. It’s barely worth John Mason getting out of bed in the morning. “There is a serious point to be made here. 49% of voters in John Mason’s Glasgow Shettleston constituency backed Scotland remaining in the UK. The idea that an SNP MSP will refuse to deal with No voters is an insult. An MSP is elected to serve all constituents, not just those who agree with him or her. It’s time for John Mason to grow up and stop trying to divide people based on how they voted in a referendum.”
A SNP spokesman said: “All individuals and businesses are entitled to express their point of view and contribute to political debate, and we do not seek to influence people’s consumer choices on the basis of those views.”