Fianna Fáil did not get much time to bask in its first bit of good news in four years. About 36 hours was the sum of it.

Then, unannounced, Averil Power launched a torpedo at the party from the plinth of Leinster House. The Dublin Senator announced she was resigning from the party with immediate effect.

Her departure was cruel and brutal in both its timing and its sentiments. Fianna Fáil TDs said they thought it bad form that she did not contact Micheál Martin or anyone in the party before announcing it to the media.

On Saturday, the party had had its best day since the nadir of 2011, with Bobby Aylward winning the Carlow-Kilkenny byelection. This took the wind out of its sails.

Martin was not going to let the harsh criticisms of him go unanswered. In what became a sniping match on the News at One, he struck back, claiming the decision had more to do with the constituency of Dublin Bay North, where Power hopes to stand in the general election.

Haughey tweet

It was claimed Power was discommoded by a tweet from Seán Haughey 10 days ago that he intended to contest the selection convention for the general election. Martin claimed Power had made it clear to him in a meeting there should only be one candidate and it should be her. “She wanted me to suspend the internal democratic procedures of the party,” he said.

It is understood, too, that internal polling showed Haughey to be well ahead of her in terms of potential support.

Her resignation will come as a severe blow for Fianna Fáil and follows that of two other promising young politicians – Patrick McKee in Kilkenny and David McGuinness in Dublin West. However, not one parliamentarian yesterday said it would have repercussions for Martin's leadership.

It is clear Power felt frustrated by the slow pace of “renewal” in Fianna Fáil, and this came to a head with the same-sex marriage referendum. It is likely her decision to leave the party was made at a parliamentary party meeting in Kilkenny earlier this month when she asked TDs to campaign for a Yes vote when canvassing with Aylward. She says the suggestion was laughed at.

Martin said her description was a distortion. There was resistance to her idea. Many of the party’s TDs felt that in a traditional rural constituency, “doubling-up” with a Yes canvass was not a good idea.

The Irish Times has spoken to most of the party's younger and more prominent TDs. There was remarkable symmetry in their response. Most were unhappy at the manner in which she resigned. Beyond that, without exception, all said they were sad to see her go.

In many ways, Power was the exemplar of what a renewed Fianna Fáil should stand for – young, female, liberal, with strong ideals and an excellent work ethic.

Realities of politics

But some said she failed to understand the pragmatic and prosaic realities of politics. “There was always going to be some tension between modernisers and those who were reluctant to move as quickly,” said one TD. “The realpolitik of it for Fianna Fáil was that if we moved too quickly we would lose some of our constituency.”

"We are trying to accommodate a broad church," said Billy Kelleher. "As a politician you have to accept you cannot always get your perspective and ideas across the line."

Power says she will not join another party. It’s a racing certainty she will stand as an Independent. Her chances might be better than if she had stayed within the party fold.