The Sinn Féin President Mary Lou McDonald has dismissed calls for the party to end its policy of abstention from the British House of Commons.
Taoiseach Leo Varadkar believes the party should use its votes to boost support for the Brexit deal.
A vote on the agreement will take place in the UK on December 11.
Ms McDonald claims the Taoiseach has not thought through his idea.
She said: "Anybody who imagines that Sinn Féin riding in on our white charger to rescue Theresa May and the deal, that that would work out without a whole series of very powerful and very disruptive political dynamics being unleashed hasn't really sat back and thought about this.
"That is what I suspect is the case with Leo Varadkar."
- Digital Desk