The deputy prime minister of Ireland has tendered her resignation, a move that is likely to stave off a government shutdown and snap election.

Frances Fitzgerald's decision to step down on Tuesday came after mounting pressure over the handling of a whistle-blowing corruption scandal within Ireland's Garda police force.

Irish members of parliament were slated to vote later on Tuesday on a no-confidence motion, filed by the opposition, in Prime Minister Leo Varadkar's minority government.

But now, following Fitzgerald's decision to quit as deputy prime minister and minister for business, enterprise and innovation, no such vote is expected to take place.

In announcing her resignation, Fitzgerald insisted she had done nothing wrong, but said she was standing down "to avoid an unwelcome and potentially destabilising general election at this historically critical time.

"It has been the greatest honour of my life to serve in government," Fitzgerald said in a statement, shared by the Irish Times newspaper on Tuesday.

"Throughout my career I have always sought to act with integrity and responsibility, and that is why I have decided on this occasion to put the national interest ahead of my own personal reputation," she said.

The political uncertainty came in the run-up to crucial Brexit talks at a European Union summit in mid-December, where Dublin is expected to pressure the UK government to clarify how it can keep the Ireland-Northern Ireland border free of customs posts and other barriers when Britain leaves the bloc.

Ireland is a member of the EU, while Northern Ireland is part of the UK.