Labour leader Eamon Gilmore is to face two motions of no confidence.
Seven TDs and one senator have submitted a motion to Labour's Parliamentary Party meeting on Wednesday night.
The motion has been signed by TDs Ciara Conway, Dominic Hannigan, Michael McNamara, Ged Nash, Derek Nolan, Aodhan O Riordain and Arthur Spring, as well as senator John Gilroy.
It means the Tánaiste will face a potential vote on whether to remove him as party leader.
He will then face a separate motion of no confidence at the party's Central Council.
It's understood that meeting is not due to be held for two to three weeks.
The subject of the party's leadership is also likely to be raised at this week's meeting of the Labour Parliamentary Party, which is expected to be held on Wednesday:
