Fianna Fáil leader Micheál Martin has said there won't be a general election this year unless the Taoiseach tries to "pull a stroke of some sort because he thinks it will benefit him."
There has been growing speculation that Mr Varadkar may go to the country if there is a Brexit extension or if a deal is secured.
Speaking at the Fianna Fáil presidential dinner in Dublin, Mr Martin said that it will then be “up to him [the Taoiseach] to explain himself if he decides that we actually don’t need to complete parliamentary scrutiny of the Finance Bill, the Welfare Bill, and of course the supplementary estimates caused by his ministers failing to deliver projects without massive delays and overspending.”
Mr Martin also accused Fine Gael of previously trying force an election during a period of political instability caused by Brexit.
“When other parties, including Fine Gael, were trying to force a period of instability through collapsing the Dáil and Government we took a different approach.
Budget
"In spite of many, many reasons to force an election we said that Ireland couldn't afford to be left without a voice in Brexit and had to show to Europe and the world that the Brexit madness would not be let into our politics."
In relation to the budget, Mr Martin said the Taoiseach had “some neck” in trying to claim credit for policies which Fianna Fáil demanded, including the funding of the national purchase treatment fund.
Mr Martin also said the party is thinking of former taoiseach Brian Cowen, who has been unwell recently.
“I want to say to the Cowen family how much we are thinking of our friend Brian as he is on the road to recovery. His passionate commitment to his family, his community, his friends, his party and his country has always defined him. We wish Brian a speedy recovery.”
Speaking to journalists before the event, Mr Martin also said the party will be going into the next general election in an “even stronger position than we went into the 2016 general election, and we will win additional seats.”