RTÉ will make a decision later on whether the Sinn Féin leader will be allowed into the final televised debate of the election campaign.
The party is calling for Mary Lou McDonald to be included in tomorrow nights programme, instead of a head-to-head between Fianna Fáil and Fine Gael.
Micheál Martin and Leo Varadkar are set to go head-to-head on Prime Time on Tuesday.
Sinn Féin's director of elections met the national broadcaster yesterday and raised the exclusion of its leader.
RTÉ says its approach to leaders' debates are based on "empirical data" and it will give "due consideration to any representation made".
People Before Profit and the Labour Party say the final TV debate of the election campaign should include more than Fianna Fáil and Fine Gael.
Bríd Smith says the election is still wide open and people are entitled to hear a broader range of views.
"It is an attempt to exclude the leader of the third-largest party when it's clearly evident that this wouldn't happen had this been Labour," said Ms Smith.
"More generally, all party leaders should be invited to attend. We don't live in a two-party state.
Brendan Howlin, meanwhile, is calling for a repeat of the seven-way debate.
"I don't think you can simply choose two individuals, representing two parties...and exclude all others," said the Labour Party leader.
"So I think a repeat of the seven-way debate that includes all shades of opinion and all potential component parts of any future government should be afforded the opportunity to debate."
According to the latest Sunday Business Post/Red C poll, Sinn Féin is on 24%, up 3% on last week.
The poll shows that Fianna Fáil is down two points to 24%, while Fine Gael is down two points to 21%.