Such an agreement would allow information to be shared between the tax authorities of both jurisdictions, and will alarm Irish residents who have been using Isle of Man banking facilities to evade tax at home.

Offshore deposits on the Isle of Man have also been featuring prominently in the ongoing tribunal hearings in Dublin into allegations of planning corruption and of undeclared payments made to politicians by business leaders.

According to the former chairman of the Irish Public Accounts Committee, Jim Mitchell, Irish banks and building societies based on the Isle of Man hold more than 5bn euros (£3.17bn) on behalf of residents of the Republic. That figure is more than double the amount per capita held by British residents, he claimed, and raised questions about the tax status of much of the money.