Fianna Fail leader Michéal Martin has once more ruled out going into government with either Sinn Féin or Fine Gael.
Mr Martin made the comments ahead of his party's Ard Fheis, which has started in Dublin
In his opening address, Mr Martin noted the party's success in last year's General Election and said that since then, great strides had been made by the organisation.
Fianna Fáil delegates voted this evening not to enter into a coalition government with Sinn Féin under any circumstances.
The Ard Fheis is being held against the backdrop of Tuesday's Budget, which Fianna Fáil facilitated as part of its confidence and supply agreement with the minority coalition.
Although Fianna Fáil has agreed to facilitate one more budget, it - like many other parties - is already preparing for the next electoral contest and is selecting candidates around the country.
With 45 TDs and 13 Senators, Fianna Fáil wants to build on its 2016 performance.
Mr Martin accused the Taoiseach of having "nothing whatsoever" to say about improving health services, developing education or addressing the lack of delivery despite Leo Varadkar's "urgent need to communicate more".
He also accused the Government of a "spin campaign" and criticised Mr Varadkar over the establishment of a new communications unit.
Mr Martin said Government was failing vulnerable children and the more Fine Gael talked about caring for children, the worse the situation got.
The Fianna Fáil leader also called for a new departure in relation in children's services and suggested that ministers Katherine Zappone, Simon Harris and Eoghan Murphy update the Dáil every two months on child homelessness and vulnerable children.
"If they are so committed to communicating and talking, let's start by talking meaningfully about our vulnerable children", he said to applause.
In relation to the Eighth Amendment, Mr Martin said the freedom of conscience principle will apply to Fianna Fáil as the Oireachtas considers its position.
He said divergent opinion needed to be respected and tolerated.
He also said he had not changed his mind about former Fianna Fáil taoiseach Bertie Ahern rejoining the party.
The Ard Fheis is being held in the capital where it wants to win seats in the five Dublin constituencies where it has no Dáil representation.
Over the weekend, delegates will vote on around 135 motions. Many focus on key areas such as health, housing and Brexit.
Tomorrow there are motions adopting contradictory approaches on the Eighth Amendment, which acknowledges the equal right to life of the mother and the unborn.
The Ard Fheis will close tomorrow night with a televised address by Mr Martin.