Labour and the SNP clashed again yesterday over the cost of Scotland's advert for Homecoming Scotland.

Labour claimed that the clip, which features the likes of Lulu, Amy Macdonald, Brian Cox and Sir Sean Connery singing lines from Dougie MacLean's popular song Caledonia, had cost more to make per minute than Slumdog Millionaire, the Oscar-winning film.

Lewis Macdonald, Labour tourism spokesman, compared the £233,450 cost of making the 60-second advert to that of Slumdog Millionaire, by dividing up a budget of £3.3m by the length of the film, 120 minutes, and arriving at a figure of £28,000 per minute.

Transmission costs were £299,287 and while none of the celebrities taking part received a fee, their expenses added a further £1550 to the bill. An edited version of the advert to screen in the US cost £10,000, while music usage for a year added another £15,000.

Mr Macdonald said: "I am astonished that the SNP's Homecoming advert cost more per minute than a film that won eight Oscars. They'll certainly not be winning any prizes for getting value for public money."

He challenged First Minister Alex Salmond to explain why the advert was so expensive. "The SNP began by trying to remake Brigadoon with SNP supporters Sean Connery and Sandi Thom in the lead roles. Now it turns out that they did so at prices which are more Hollywood than Holyrood."

An aide to Jim Mather, the Enterprise Minister, claimed Mr Macdonald was mistaken. He said: "This is another embarrassing blunder by Lewis Macdonald. In a bizarre attempt to talk down the wonderful year of Homecoming and bad-mouth an advert in which all stars gave their time for free, Mr Macdonald has got his facts all wrong.

"As well as being wrong about Homecoming, Labour are even wrong about Slumdog Millionaire, the production costs of which were some five times the figure they claim."

He added: "The bottom line is that the Year of Homecoming is set to deliver £40m extra in Scottish tourism revenue and 100,000 additional visitors, turning around a threatened downturn and giving our tourism industry a huge boost in a tough economic climate.

"The Labour Party need to decide whether or not they support this fantastic initiative for Scotland. Mr Macdonald's press release is also hugely disrespectful to all of the Scottish stars who all gave their time for absolutely nothing, including Brian Cox, who has been a prominent Labour Party supporter."

A Scottish Government spokesman said: "These are inaccurate claims about a great advert for Scotland."