Former agriculture minister Dara Calleary has resigned as deputy leader of Fianna Fáil, the Taoiseach has confirmed.
Micheal Martin said that Mr Calleary has also resigned as national secretary of the party and that his colleague is "very, very sorry" for attending a golf dinner during the pandemic.
It comes days after the Mayo TD resigned as minister for agriculture in wake of the golf society dinner in Galway.
Mr Martin said Mr Calleary volunteered to step down from the roles.
Mr Martin told RTÉ's Today with Claire Byrne: "He knows he did wrong, he knows he got it wrong and he understood the key point that the actions by him... he doesn't play golf, but by going down to speak he essentially was undermining the authority of the Government to bring in restrictions."
Gardai are investigating whether coronavirus regulations were broken in holding the Oireachtas golf society event two days after the Government announced it intended to curb the numbers permitted to gather together.
A resurgence in Covid-19 cases in recent weeks has led Ireland to backtrack on some of its plan to reopen society after lockdown.
The function was held across two rooms in the hotel in Clifden.
Supreme Court judge Seamus Woulfe was among others on the guest list.
Mr Martin said he could not call for the former attorney general to step down as there is a separation of powers.
"I don't believe he should have been at that event, but I think within the judicial arm of government, the judicial arm have to deal with this. The political arm of our constitution can't deal with it," he added.
Mr Martin also denied that the Government is falling apart, adding that it is "tenable".
"It will survive. I've had good meetings with (Tanaiste) Leo Varadkar, with Eamon Ryan in terms of these key issues," he added. "There will be challenges."
The Taoiseach will also be speaking to the Ceann Comhairle on Monday to agree a date for the Dail to return, which is expected to be next week.
Meanwhile, Minister for Housing Darragh O'Brien said that it "makes sense" for the Dail to reconvene after the schools have reopened.
Mr O'Brien also said that he believes the Government is clear in its communication in Covid-19 restrictions.
He added: "There's no question that it is more complicated as a country moves out of restrictions and tries to deal with different sectors differently and that's appropriate that that be done.
"It is complex, but yet where there have been fomenting communication that will be rectified and is being rectified.
"I think fundamentally our message has been really clear, that all our priority from the three-party government is about our schools reopening, our kids getting back to work, the July stimulus plan that supported tens of thousands and hundreds of thousands of jobs across this country."