Despite consistent polls showing support for a yes vote, the no supporters are confident that the pollsters will be just as wrong as on 2 June last year when 50.7 per cent of voters plunged the EC into crisis by voting no.
Mr Cash, like Lord Tebbit and Tony Benn before him, was invited to Denmark, the no campaign says, not to stir up trouble but to add to the impression that it is respectable to reject Maastricht.
'The government has concentrated on terrifying people with apocalyptic visions of what will happen if we vote no,' said no campaigner Bo Wermus. 'Britain and Denmark are in lots of ways similar countries. British politicians are not meddling. They are just here to provide moral support.'
His views, unsurprisingly, are not shared by the Danish government. A visibly annoyed Foreign Minister Niels Helveg Petersen last week treated reporters to selected extracts of unhelpful press comment, then said: 'We should be left to fight our own campaign. The British should fight their own battles in Britain.'
Mr Cash was at pains to tell his audience: 'I have not come to tell you what to think, but because this is fundamentally a European issue and the Danish and British people are in it together.'
Across the other side of the city, Mr Heath was exhorting the Danes to vote yes, although it was not clear whether he had been invited to do so or had come of his own accord, as his host, former Danish prime minister Poul Schluter suggested. He later apologised for confusing people: 'I invited Edward Heath but I knew the answer in advance.'
The truth is probably that ordinary people do not particularly care what the British think. The no camp is a broad church, including those who believe that the treaty does not go far enough in making the kind of social provision that is an anathema to the Conservatives. The audience that applauded Mr Cash would not have looked out of place campaigning against cruise missiles. Many could have been that other thorn in Tory flesh, New Age Travellers.