The former Prime Minister and the business mogul, who have more than 80 years' involvement in politics between them, accused each other of lying about what Sir Edward did or did not know in 1960 about the future of the community.
Neither, however, seemed likely to press their allegations in a court of law. "I'm not likely to take legal action against a multi-billionaire who is trying to buy the country's vote with pounds 20m," Sir Edward said of his former Conservative Party colleague.
The row started when Sir James launched News, his Referendum Party's new national newspaper, with a story about how the Heath government had "lied through their teeth" to the British public on the consequences of joining the Common Market. A letter sent to Sir Edward in 1960 by the then Lord Chancellor, Lord Kilmuir, talked of "serious surrenders of sovereignty" and added that his objections "ought to be brought out into the open", according to the paper.
But, it added, Sir Edward told the voters that "there is no question of any erosion of essential national sovereignty".
Sir Edward was having none of it. He had been taken out of context, he complained, and Sir James was "cheating".
When he had said there would be no erosion of national sovereignty, he had added: "What is proposed is a sharing and an enlarging of individual national sovereignties in the general interest," he said.
A copy of the letter revealed that that, too, had been selectively quoted. While it did mention sovereignty and said that the there would be objections on those grounds to joining the Common Market, it added a rider which was not mentioned by Sir James' newspaper.
Although such considerations should be given due weight because of their political implications, "I do not for one moment wish to convey the impression that they must necessarily tip the scale," he said.
Sir James was merely seeking publicity, Sir Edward suggested, and a high- profile libel case would simply create it. But although he brushed aside suggestions that he might go to court, he said he would continue to make his position clear. He said that what the EC nations were doing was not surrendering sovereignty, but pooling it. Britain had gained influence over other countries as well as winning trade as a result, he argued.