Former Irish presidential candidate Peter Casey will run for election against Taoiseach Leo Varadkar in his Dublin West constituency.
The Londonderry businessman is also running for election in Donegal, where he owns a property, and says he will not be canvassing for votes in Dublin.
Mr Casey cannot vote in the elections as he is currently a resident of the United States.
Speaking to media after submitting his nomination papers on Wednesday, Mr Casey denied the move was a stunt.
"It's not a stunt - obviously I am passionate about getting elected in Donegal, that's where my business is, that's where my home is, and I want to represent the people of Donegal," he said.
Asked why he is also running in Dublin West, Mr Casey said: "I am going to give people 10 reasons why they should not vote for Leo Varadkar.
"Top three... he had to ask a barrister the difference between right and wrong in regards to the Maria Bailey scandal (former Fine Gael TD who was involved in a claim against a hotel); he was the minister for health when the National Children's Hospital went off the rails with the budget; the biggest housing crisis in the history of the state.
"I think he'll go down as the worst Taoiseach in history."
The Londonderry-born businessman finished second behind Michael D Higgins in the presidential election in 2018, securing 342,727 (23.3%) votes.
Mr Casey said he was "returning the compliment" by running in Dublin West as he claims Mr Varadkar discouraged people from voting for him in the presidential race.
"In the presidential election, Leo Varadkar almost breached the constitution by telling people not to vote for me, and I'm just returning the compliment," he said.
"I want to give people in Dublin West the opportunity to register their disgust with the way he has behaved.
"He's not fit to be Taoiseach and shouldn't be Taoiseach. Anyone but Leo."