Mary Lou McDonald has used a speech at the centenary celebration for the first female MP to reaffirm her party's stance on abstentionism.
The Sinn Fein leader spoke on Saturday at an event dedicated to Constance Markievicz, who was elected to the House of Commons as an abstentionist Sinn Fein MP in 1918.
The party have come under renewed calls to revise their policy and take their seven seats in Westminster.
As the vote on the draft Brexit agreement nears, Taoiseach Leo Varadkar called on Ms McDonald's party to give up the seats to representatives who would take them, enabling them to vote in the critical ballot next week.
Sinn Fein have remained steadfast in their policy that they will not take their seats in the House of Commons or pledge allegiance to the Queen, a point reiterated by Ms McDonald on Saturday, before taking aim at her political rivals.
"These revisionists celebrate the election of Markievicz as the first woman elected to Westminster, as they should," Ms McDonald said.
"What they ignore is her principled abstention from that parliament, her pledge to never take an oath of allegiance to the power she meant to overthrow.
"These revisionists attack Sinn Fein for that same principled stance. That unwillingness to take an oath of allegiance to a foreign power.
"I ask those revisionists: would they take that oath?
"One hundred years on and Constance Markievicz remains a troubling figure for those in power.
"Because she stands against the hypocrisy of Irish political leaders calling on others to swear an oath to a queen.
"Because she reminds them than no republic worthy of that title would tolerate homelessness or partition or would be a home to poverty and inequality.
"What would she make of this Dail and the partnership of Fianna Fail and Fine Gael?
"Parties that take the side of the landlords. That have stolen the dream of many to own a home. That stand over a system in which a working wage is not a living wage.
"What would she make of a Dail that still behaves like a boys' club?
"What would she say to Leo Varadkar and Micheal Martin?
"My guess is that she would have a lot to say. She isn't here to say it.
"So we must. We will, and we will be heard."
In a reference to Northern Ireland, Ms McDonald noted lack of marriage equality, abortion rights and the Irish Language Act, which has seen Stormont deadlocked for almost two years.
"What would she (Markievicz) say about the continued partition of our country? What would she say about the denial of basic rights to our people - the right to speak our language, to health care and to love and marry who we want?
"We must continue on the road to true equality and finishing what they started - we must continue the fight for a new, inclusive, united Ireland."
The event, held at the birthplace of Constance Markievicz in Lissadell House, Co Sligo, discussed themes such as the power of the vote, and the 1918 election.