Brothers Craig and Brian Halley have made Slanj, which has shops in Glasgow and Edinburgh, into one of the country's most talked-about designer outlets for their contemporary kilts and humorous T-shirts.

But their interpretation of one of the biggest events in Scottish history – the 2014 Commonwealth Games – has not gone down well with the organisers.

The company set up to run the Glasgow Games are now threatening Slanj with legal action unless they withdraw a range of T-shirts that depict characters taking part in "traditional" Glaswegian sporting pursuits.

Four white boxes over the words "Glasgow 2014, Commonwealth Games", contain figures playing pool and darts, watching TV and sinking a pint of beer.

Slanj owner Brian Halley said: "We specialise in quirky T-shirts and this is just meant as a joke, our take on the real games that real Glaswegians indulge in. It was an attempt to join in the fun surrounding Glasgow getting the Games."

But a spokesman for Glasgow City Council, which is part of the partnership company running the event, said the Glasgow Commonwealth Games 2014 logo had been registered in the UK as a trademark, a design and a wordmark to prevent unauthorised material being sold.

"It therefore has legal protection in all these categories," he said.

"In the instance of Slanj, if they are selling 2014 Games branded materials, then this will be followed up through the 2014 legal team.

"The organising company would not be against a little bit of humour or harmless fun, but use of the brand means that it could not ignore this application. We would ask Slanj to remove the items from sale."

Halley said he was "sorry" if the T-shirts, which cost £20, had caused offence. After the current batch had been sold, the design would be changed.

Slanj was established in 1996.

Among its customers are Irvine Welsh, Sir Sean Connery, Ewan McGregor and Jonathan Ross.