The sudden resignation of Bertie Ahern as Irish prime minister, less than a year after winning a third term in office, came as a political bombshell in Dublin on Wednesday, yet it should have been predictable.

As Taoiseach (the Irish term for prime minister) since 1997, Mr Ahern had come to personify the success of the booming Irish economy – the so-called Celtic tiger. He also took the credit with Tony Blair, his British counterpart, for the successful negotiation of the Good Friday agreement that brought peace to Northern Ireland. He was even mentioned as a possible contender to become the first semi-permanent president of the European Council, if and when that job is created after the ratification of the Lisbon treaty reforming the European Union.