Irish agriculture Minister Dara Calleary has resigned after attending an indoor golf society event with 80 other people.
A number of other politicians also attended the event, including Fine Gael Senator Jerry Buttimer and Independent TD Noel Grealish.
Other guests included EU Commissioner Phil Hogan and former Attorney General Seamus Woulfe.
The Oireachtas Golf Society event was held at the Station House hotel.
Current guidelines state that no more than 50 people should gather indoors.
Mr Calleary cancelled a number of media appearances he was due to make on Friday morning before his resignation was confirmed.
He resigns from the Cabinet five weeks after his was appointed to the role following the sacking of Barry Cowen.
Mr Cowen was sacked after he refused to provide further public statements on his 2016 drink-driving offence.
Mr Calleary apologised in a statement issued on Thursday night.
He said: “Last night I attended a function I committed to a number of weeks ago, to pay tribute to a person I respected and admired greatly.
“In light of the updated public health guidance this week I should not have attended the event. I wish to apologise unreservedly to everyone.
“We are asking quite a lot from everyone at this difficult time.
“I also offer this apology and my sincere regret to my Government colleagues.”
Taoiseach Micheal Martin is expected to issue a statement in the coming hours.