The Fianna Fáil leader Micheál Martin has accused the government of lacking the urgency or ambition to tackle the problems facing the country.
Micheal Martin made the comment in speech at the annual Wolfe Tone commemoration in Bodenstown Co Kildare.
He claimed the government is "drifting" and said ministers were failing to engage with the issues.
Mr Martin's also warned that Brexit poses a "deep and rising threat" to Ireland.
He claimed that since the Brexit vote, "the actions of the London government have been little short of shambolic".
British cabinet ministers responsible for Brexit had been "cavalier and grossly unprofessional", according to the Fianna Fáil leader.
He accused the Tory government of being dismissive of Northern Ireland and Scotland, despite the fact they voted in favour of remaining in the EU.