Craig Ferguson, the Scottish-born US chat show host, has been described as a "traitor" after telling millions of American TV viewers that his home town, Cumbernauld, is the worst place in Britain.

The man who started his career in Scotland as comedian Bing Hitler before becoming a household name on national US TV, derided the regenerated town on his Late Late Show on CBS with the 44-year-old UK journalist, documentary filmmaker and best-selling author Jon Ronson in a slagging session which lasted two minutes.

Referring to The Idler's Book of Crap Towns, which rates Cumbernauld second only to Hull, Ferguson said: "It's a pretty horrible place. It usually wins the prize for the second-worst town in the UK. And I have been to Hull and it is bad, but it is not as bad as Cumbernauld."

Ferguson, 49, who is among the most popular talk show hosts in the US, agreed as Ronson, whose wife is from Cumbernauld, said: "Hull's got rivers, at least it has got a river. The only water Cumbernauld's got is urine, sort of flowing ...

"Everything's broken, all the windows are broken, all the doors are off their hinges."

When Ronson said he was perhaps being a bit hard on Cumbernauld, the Scot, who is now a US citizen, retorted: "No you're not. You're being very gentle on Cumbernauld. Listen, don't get me wrong, I love Scotland. I think it's the other greatest country in the world. But I have to say, there's one problem in Scotland: Cumbernauld."

His comments have been branded "absolute nonsense" and out-of-date by those responsible for the regeneration of Cumbernauld, which has twice been given the Carbuncle award by architecture magazine Prospect for the worst-designed town.

Councillor Gerry McElroy, chair of the North Lanarkshire Council-formed company set up to facilitate the redevelopment of the town, said: "He has no justification for forming an opinion like that. He's a bit of a traitor going on national US TV and talking this town down.

"I don't see any reason to be so derogatory about Cumbernauld. Everything that's been said is absolute nonsense and just not justified. When was he last in Cumbernauld? There is nothing said in this interview that describes Cumbernauld as it is right now. It is ridiculous to paint such a picture."

Ferguson is said to be on the verge of becoming one of the US's richest TV stars by doubling his reputed £8 million annual salary with CBS.