Tunnock's has been accused of ditching its Scottish heritage with a new campaign promoting its famous treat as "the Great British Tea Cake" in England.
Managing director Boyd Tunnock said the London Underground advert is simply a nod to the hit BBC show the Great British Bake Off, but the move has angered some Scots who say it is a rejection of the Lanarkshire-based firm's Scottish roots.
On Twitter, one SNP member said: "Re-branding is one thing - what Tunnocks did was a brazen rejection of Scotland."
Another independence supporter said: "Imagine if Guinness had said they wouldn't promote Ireland or Toblerone saying they wouldn't promote Switzerland."
Conservative voter Mr Tunnock, who spoke out in favour of the Union during the 2014 referendum debate, said the furore was a "storm in tea cake".
He told Radio Scotland: "The advert we put in London was a sort of spoof of the British Bake Off. It was my son-in-law who suggested this and I thought it was okay."
But he later told Radio 2's Jeremy Vine show: "We're in Britain, that's what we say.
"We are advertising the Great British Tea Cake because we had a referendum here and 55% of Scottish people wanted to be in Britain and that's why we're calling it the British tea cake."
Mr Tunnock said the lion rampant image has not been removed from the packaging, as some people had suggested.
He said he sent a box of the treats to First Minister Nicola Sturgeon as well as to Prime Minister David Cameron for Christmas, and a packet is also making its way to "the Labour man".
The family firm established in 1890 and based in Uddingston sells around 3.5 million tea cakes a week.
Asked about the effect of his comments during Scotland's independence debate, Mr Tunnock said: "I did get a few letters from folk saying 'our extended family of 11 will never buy another tea cake', but since then we've sold even more and more, because they are nice - they are good."