Fianna Fáil's only remaining MEP has announced he's changing his group in the European Parliament.
Brian Crowley is to leave the liberal-leaning ALDE group and join the European Conservatives and Reformists - the Eurosceptic group set up by David Cameron's Conservatives five years ago.
In a statement Mr Crowley said the move would "allow me to provide a better service for my constituents", as the ECR group would allow him to retain more Irish staff.
It's believed Mr Crowley had reached stalemate in talks with the ALDE group over whether he would be allowed to retain the same level of staff he had previously enjoyed, which were impacted by the loss of the other two Fianna Fáíl seats in last month's European elections.
"I also made this move to protect some jobs of Irish staff in Brussels, and not for any personal gain for myself, except my new Group will allow me work more effectively for my constituents in Ireland South," he said.
He described the ECR as a "non-federalist, pro-EU group who believes in giving a much stronger say to National Governments rather than to EU Institutions".
"The ECR Group is now the third biggest group in the EU and its priorities include creating long-term jobs and prosperity for member countries, which matches my policy priority."
The move is a major blow to Fianna Fáil leader Micheal Martin, who is understood to be deeply unhappy with the news.
Crowley's status within Fianna Fáil is now unclear, as Fianna Fáíl itself is still a full member party of ALDE - with former minister Dick Roche still serving as a vice-president of the group.
The move also comes as something of a surprise given the difference in European views between ALDE and the ECR - with the latter being seen as favouring deeper European integration, the latter opposing it.
The ECR's biggest membership blocs are the British Conservative Party, Poland's Law and Justice Party, the new eurosceptic party Alternative for Germany, and the nationalist True Finns,
Given that Mr Crowley is Fianna Fáil's only MEP, it remains to be seen whether the party will now follow his lead and embrace a more sceptical stance to European affairs, or whether Crowley - who was widely seen as an independent operator, and whose campaign literature featured only small Fianna Fáil and ALDE logos - will now cut ties with the party entirely.
