The campaign (MARC), set up with leading anti-Maastricht campaigner and MP William Cash as a founding member, had sought an injunction to prevent further publication of confidential details of its bank account revealed by Hounam in his column on 14 May.
Mr Justice Parker dismissed the application and refused to grant an order requiring Hounam to disclose his source for information that a payment of £249,994 had been paid into MARC’s Barclays Bank account by a “mystery customer” of the Swiss bank Credit Suisse.
The judge said there was evidence that MARC’s bankers had been tricked into revealing information about entries to its account but there was, as yet, no evidence as to the identity of the trickster.
Hounam had told UKPG he had no intention of revealing his source.
After the case, he said; “I am delighted. It is a good day for press freedom.”
Hounam told the judge he had received the information quite unexpectedly from a personally confidential source he had dealt with in other stories.
MARC claimed that the breach of confidence could discourage future donors.
Although MARC had a seriously arguable case that Hounam was under a duty of confidence to them, said the judge, there was a strong case in favour of the material being disclosed in the public interest.
“It seems to me that the fact that such a large sum has been received, and received from abroad, is a matter of public interest,” he stated.
The information was now in the public domain and it was difficult to see how details already published in the national press could still remain confidential.
The judge took into account the fact that if an injunction had been granted it would have been binding not only on the Daily Mirror but on the whole of the press.
Hounam told UKPG: “If the campaign is worried about its fundraising, what on earth are they doing spending substantial sums of money on futile legal actions against the press?
They are now faced with having to pay our costs as well as their own, and I think they will be up to £25,000 the poorer.”