The men were given a "stern warning" after causing a major security alert on the M6.

All four were wearing purple crushed velvet suits similar to those worn by spoof superspy Austin Powers in the film The Spy who Shagged Me.

Police saw the funny side

The alert began when police received several calls from terrified motorists who said a small handgun had been pointed at them from the open windows of a Ford Fiesta.

Officers from the Staffordshire and West Midlands police forces used a rolling road block to halt the car on the northbound carriageway near Stone, Staffordshire, slowing down traffic between junctions 14 and 15.

Staffordshire Police said the men, all in their 20s and from the London area, were on their way to a "70s convention" in Wales.

They gave the men a severe warning, and seized two toy guns, before allowing them to continue their journey to Prestatyn, north Wales.

A spokesman said that although police could see the funny side, hundreds of motorists had been inconvenienced by the group's "stupidity".