‘I’ve got the appetite,’ says Micheál Martin – but for how much longer can he and Eamon Ryan hang on?

Shortall and Murphy managed seven and a half years since the creation of the new party in July 2015. Their creation has stayed the course, even if a third co-leader in the shape of Stephen Donnelly did not.

Yet, as Shortall put it: “Catherine and I have decided that the time is right now to hand over the reins to the next generation of Social Democrats.” She said they were taking the “advice that we so often gave to government”.

Whoops – that’s a government that includes Martin, leader of his party since January 2011, and Ryan, leader of his since May of the same year. So that’s 12 and one month for Micheál, and coming up close on 12 for Eamon.

But with Martin losing the power of the Taoiseach’s office and the Greens toiling as junior coalition partners, for how long more can two great survivors of Irish politics cling on?

The question is increasingly occupying the minds of the spear-carriers in both parties, and the sage and measured departures of Shortall and Murphy – and other examples internationally – will start tongues wagging anew.

Martin is a super-fit 62 and Ryan only 59 – both of them younger than the outgoing Social Democrats co-leaders – but the political age at the helm is starting to look faintly ridiculous.

Ryan withstood a leadership challenge from his deputy leader, Catherine Martin, when he had to offer himself again following the last general election, under party rules. The surprise was not that he prevailed, but that she did so well. He polled 51.24pc of the membership vote to the Arts and Tourism Minister’s 48.76pc. That is a frighteningly close margin, but Ryan has sailed blithely on while Ms Martin has knuckled under.

At least they tested member opinion. Over in Fianna Fáil, the Tánaiste is beginning to rival the longevity of the man now readmitted to the party, Bertie Ahern.

The difference, of course, is that Ahern won the party three general elections in a row, and Martin hasn’t actually won any.

There seems no real logic to such a sustained career at the top of a major party, all the more so since he has never been openly challenged in the past dozen years – just whispered against by a grumpy rump, at different levels of intensity to suit the times. And the grumpy rump has advanced in age with Martin’s evergreen endurance. They no longer offer any form of alternative from within their number.

Perhaps some of them are feeling nostalgia for the days of Charlie Haughey, who took over in 1979, two years after the last election in which any Irish political party won an overall majority. Haughey led for 12 years and three months.

Martin will exceed that impressive record in May, yet Haughey faced three bitter heaves within his party.

He was also the man who quipped that “some of these Chinese leaders go on into their 80s,” as if he intended doing so himself. He was around Martin’s age at the time.

Of course whether to stay at the helm is up to the individual, and the Tánaiste told Newstalk on Thursday: “I have a lot to give.”

That happened to be on the day an opinion poll found that Fianna Fáil was down three points, trailing Fine Gael by four.

“I’m looking forward to this new phase of this Government and also this new phase of politics,” the Tánaiste said.

“I haven’t lost any appetite.”

But that begs the question: Where on earth is the appetite – within both Fianna Fáíl and the Greens – of the hungry and ambitious, known in politics as the Young Turks?