Mr Harris is travelling to Áras an Uachtaráin to trigger what will be a relatively short three-week campaign ahead of polling day on Friday November 29.
It will bring to an end the four-and-a-half-year lifespan of the Fine Gael, Fianna Fail and Green Party coalition government.
Mr Harris made a brief speech at Government Buildings, before heading to Áras an Uachtaráin to seek the dissolution of the Dáil.
He said that while Fine Gael and coalition partners did not always agree on every issue, they delivered five budgets, during difficult times including the Covid pandemic, and the fallout from Russia’s illegal invasion of Ukraine.
He said voters’ support should never be taken for granted and added: “I ask just one thing of the Irish people – value your vote, use your voice – that’s how this country works
“Ladies and gentlemen, if you give me your trust, I will give you my all.”
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Fianna Fáil leader Tánaiste Micheál Martin has said he has “no worries at all” about upcoming television debates and going head-to-head with the Taoiseach.
He said he is looking forward to debates because his party will put forward its policies and priorities.
“I love campaigning, I have been about the length and breadth of the country and I will continue to do that,” he said.
He said Fianna Fáil will campaign to reduce prices, on the cost of living on families and households, on housing as well as health.
“We have been the agent of change in housing over the last number of years, we’ve engineered change and new departures in housing policy.”
He said Health Minister Stephen Donnelly’s “radical” interventions on women’s health have been a “game changer”.
“We want safer cities and safer urban areas,” Mr Martin said.
The Foreign Affairs Minister said Fianna Fáil has a “historic mission” on making free schoolbooks for students.
“Our campaign is about the future of Ireland, the future of our society and we’re determined to invest in public services and to create a tax environment which will encourage and nurture enterprise and make us resilient against international turmoil,” he said.
He said Fianna Fáil has “ruled out” government with Sinn Féin.
“We’re very clear they don’t get the economic model, they don’t get the enterprise model, they don’t believe in free trade,” he said.
The party kicked off its campaigning this morning at Merrion Square, where the Tánaiste was joined with TD Jim O’Callaghan as well as general election candidates Mary Fitzpatrick and Catherine Ardagh.
Fianna Fáil and Fine Gael politicians have already said they will canvass the Ireland v Australia game at the Aviva Stadium tonight.