The Waterford branch of Fine Gael has voted no-confidence in sitting TD John Deasy.
The motion was passed at a constituency meeting on Monday night.
The party's national executive will now be informed.
Deputy Deasy was not at the meeting in Dungarvan, which was called to discuss Fine Gael's poor showing in the local elections last month.
Deputy Deasy has been a TD for the past 17 years, and is the Government's special envoy to Washington.
The vote was passed unanimously by councillors, local election candidates and party members.
Mr Deasy was appointed as Special Envoy to the US Congress by the Taoiseach Leo Varadkar in 2017.
He previously worked as a parliamentary aide to Republican Congressmen on Capitol Hill.
Deputy Deasy sat in on Mr Varadkar’s St Patrick’s week meeting with Donald Trump at the White House in 2018, when a potential solution to the undocumented Irish issue was discussed.
