Sinn Féin has decided to back two independents in the forthcoming Seanad by-elections, rather than run its own candidates.
The party had already clarified that it was going to support the former Senator, Ian Marshall, in the Agricultural panel - a farmer who comes from a Unionist background.
The party says it believes it is important that Northern Ireland has voices in the Oireachtas and that Unionist perspectives are included.
Another former Senator, businessman Billy Lawless, will also get Sinn Féin's backing.
The party said Mr Lawless, who had been elevated to the Seanad by former Taoiseach Enda Kenny, has a track record in working with the diaspora, the undocumented in the US and in relation to Presidential voting rights - all priorities the party shares.
The fact that Sinn Féin is backing Mr Lawless, in the Industrial and Commercial panel, will be a significant blow to the chances of Independent candidate Hazel Chu, who is also the Green Party's chairperson.
Sinn Féin said it would not be supporting government candidates or those who intend to take the government whip.
Cllr Chu had said at the launch of her campaign that it was likely she would take the Green Party whip if elected.
Under an election pact between Fianna Fáil and Fine Gael, both parties will back former Fianna Fáil Senator Gerry Horkan in the Industrial and Commercial panel and former Fine Gael Senator Maria Byrne in the Agricultural Panel.
Councillor Chu decided to stand as an Independent, after the Green Party's Executive opted neither to stand a candidate nor back a candidate.
The Labour Party has candidates standing in both panels, while the Social Democrats is not contesting the by-elections.
The two Seanad seats will be decided by TDs and Senators in secret ballot later this month.