Mr Justin Barrett, the chief spokesman of the No to Nice campaign and a leading figure in the Youth Defence anti-abortion group, has close contacts with an extreme right-wing party in Germany which the authorities there believe has "Nazi characteristics".
Mr Barrett has attended conferences and spoken at an event organised by Germany's National Democratic Party (NPD). Two years ago he attended an NPD rally in the Bavarian city of Passau as a representative of Youth Defence.
His name appears as one of the "honorary guests" at the event in Die Deutsche Stimme (The German Voice), the NPD party newspaper. The NPD described the rally, the largest by the party to date, as a day of national resistance. It was held in May 2000, and over 6,000 party members attended.
Other honorary guests included an Italian right-wing extremist and a former Nazi SS officer, who received a standing ovation.
Last month, when allegations about his links with the German organisation were first made in a Sunday newspaper, Mr Barrett threatened to sue it. He also threatened legal action against other media organisations, including The Irish Times.
Yesterday however, senior figures in the NPD and its youth wing confirmed his involvement.
"Justin Barrett was an honorary guest at our event in Passau. I invited him. He sat with the delegates," said Mr Holger Apfel, the deputy leader of the NPD. "We have been in contact with his group since 1996. We are friendly with his Youth Defence organisation."
When this was put to Mr Barrett, he declined to confirm or deny that he attended the event.
"That will be dealt with by the High Court," he said. "This is a smear campaign started by that gutter newspaper the Sunday Mirror and obviously The Irish Times is now working on it as part of this campaign by the Yes side."
The Irish Times has learned that in addition to his NPD contacts, Mr Barrett has a long-standing relationship with the party's youth organisation, the Young National Democrats (JN), a recruiting ground for the NPD. Mr Sascha Rossmüller, leader of JN, said he had been in contact with Mr Barrett "for several years". Youth Defence "shares many important interests" with the JN and is "an important part of our international network", said Mr Rossmüller. Other organisations in the network include the National Front in Britain and Italy's extremist group, Forza Nuova. The German government applied two years ago to the country's highest court to have the NPD banned. The government argues that the party poses a threat to democracy.
