A decision on government formation should have been made weeks ago, according to Sinn Féin's Mary Lou McDonald.
She said it is disgraceful that Fine Gael and Fianna Fáil have spent weeks 'shadow boxing'.
Government formation talks will resume later this morning, and both sides insist discussions will continue throughout the weekend if necessary.
Ahead of her party's Ard Fheis, Deputy McDonald defended Sinn Féin's decision not to enter government unless they were the largest party.
The Sinn Féin deputy leader has said they will not play 'make believe' by doing a deal with parties that have very different political views.
Speaking to Newstalk Breakfast, she said her party "will not be in the business of simply going into Government for its sake, or playing a game of make believe as the Labour party did last time.
"I don't relish the thought of Fianna Fáil or Fine Gael - much less the pair of them - in Government. But the result is the result... the people have cast their vote... I think what we all have an absolute right to expect - and we should have had it weeks ago - is a decision from the two parties as to whether or not they are going to get involved," she argued.
Sinn Féin's Ard Fheis gets underway at the Convention Centre in Dublin this morning, and will continue through today and tomorrow.
Gerry Adams is due to make a live television address tomorrow night, ahead of the party's commemoration at the GPO on Sunday to mark the centenary of the Easter Rising.
