The Irish prime minister, Simon Harris, has said he plans to call a general election this week, paving the way for a polling date likely to be at the end of November.

Harris is expected to dissolve the Dáil, or Irish parliament, either on Thursday before a meeting of European leaders in Budapest, or on Friday when he returns.

Under the rules, a minimum of just 18 days’ notice is required for an election, which can lead to short and frenetic campaigns.

A November or early December election has been firmly on the cards since the taoiseach announced two weeks ago he would call an election for this year rather than waiting until next February, one month before the government’s five-year term ends.

A €10.5bn (£8.8bn) budget giveaway in early October was also seen as putting the country on an election footing.

“I do intend to seek a dissolution of the Dáil this week, I don’t think that will come as a shock to any person right across this country,” Harris told reporters on Tuesday.

Harris said he would call an election once a finance bill putting the budget’s tax and spend changes into law had been passed. The bill is expected to be voted through by the Dáil on Tuesday and by the Seanad (senate) on Wednesday.

“We need to get through the business of the next few days first,” he added.

Harris leads a coalition government made up of his own party, the conservative Fine Gael, Fianna Fáil and the Green party.

Fine Gael has enjoyed a sizeable boost in its rankings since Harris, 37, took over in April from his predecessor, Leo Varadkar.

An opinion poll on Sunday put Fine Gael on 26%, Fianna Fáil on 20%, and the main opposition party, Sinn Féin, trailing on 18%.

In the last month Sinn Féin has been hit by a succession of scandals over child safeguarding in the Republic of Ireland and Northern Ireland, where it is the largest party.

Two years ago it was considered within touching distance of government in Dublin, fuelling speculation that the party would be in power both north and south of the border and accelerate the prospect of a united Ireland.

Over the past year, however, its fortunes have turned, and the prospect of being the largest party in Dublin now appears to be unlikely with a succession of polls putting it in the high teens compared with more than 30% in October 2022.

Fine Gael has eagerly seized on Sinn Féin’s woes for maximum electoral gain while at the same time deflecting attention from its own record, particularly in relation to the housing crisis, one of the opposition party’s strongest policy areas.