Two Seanad byelection counts took place in Leinster House on Friday, with former Ulster Farmers’ Union president Ian Marshall and former Fine Gael TD Anthony Lawlor taking the seats.

A former president of the Ulster Farmers’ Union Mr Marshall, an anti-Brexit campaigner who works in Queens University Belfast in the Institute for Global Food Security, was approached by Taoiseach Leo Varadkar to accept a Fine Gael nomination. He was supported by most in Fine Gael, as well as Sinn Féin.

The vacancies arose because of the resignation of Labour’s Denis Landy, who stood down from the Upper House on health grounds, and of Independent Trevor Ó Clochartaigh, a former Sinn Féin member, who left the Seanad to take up a post as communications manager with TG4.

The electorate for both byelections was comprised of TDs and senators.

Both vacancies were on the Agricultural Panel, but Mr Lawlor’s contest was for an Oireachtas sub-panel, which means candidates must be nominated by members of the Oireachtas itself.

Mr Marshall won on a so-called “outside panel”, where candidates have to be nominated by external bodies.

Sinn Féin has said its TDs and senators were more likely to vote for Fine Gael in the byelection than Fianna Fáil because of Micheál Martin’s attitude to Mary Lou McDonald’s party.

“There was no way that Sinn Féin TDs or senators were going to vote for an Fianna Fáil candidate given Micheál Martin’s relentless attacks on Sinn Féin,” a Sinn Féin spokesman said. “There is a definite resentment at Micheál Martin’s leadership.”

Sinn Féin did not run any candidate and while it recommended its members vote for Mr Marshall, it made no specific recommendation for Mr Lawlor’s panel, which included three Fianna Fáil candidates.

A senior party figure said Sinn Féin TDs and senators would rather not have supported either Fianna Fáil or Fine Gael, but added that Mr Martin’s attacks on the party made it unlikely they would back his candidates.

However, the leading Fianna Fáil opponent to Mr Lawlor was former Donegal based TD Niall Blaney.

Sinn Féin currently has one TD in the county - its finance spokesman Pearse Doherty - and wants senator Padraig Mac Lochlainn, who lost his Dáil seat at the last general election, returned as a TD.

After his election, Mr Marshall said the idea of taking a seat in the Seanad was something he had never envisaged.

“It actually came about by virtue of a conversation and call from the Taoiseach,” he said. “It was something I had never anticipated so to the Taoiseach I am hugely grateful for the opportunity.”

Mr Marshall said it was important in the context of building relations across the island that a northern unionist voice was heard in Dublin.

“I think it’s hugely important that the voices and the opinions are shared,” he told RTÉ Radio One.

Mr Marshall said he had serious fears for the economy if Brexit happened but he said he was not convinced that the UK would actually leave the European Union. He said many people in the 2016 referendum voted on the basis of “incorrect and misleading” information.

“The people probably in many cases have a slightly different perspective of this now,” he said. “I haven’t conceded the fact that we are going to leave - it looks so complex and so difficult at the moment that I believe there is a lot of discussion we still have to have.

“I think If we are truly serious about this that this should possibly go back to the people and the people it will impact most will have the chance to voice their opinion again and I firmly believe if that opportunity arises I think the people will say maybe this isn’t the right idea for the UK to Brexit.”