Irish MEP Mick Wallace was reprimanded in the European Parliament for calling Venezuelan opposition leader Juan Guaido an "unelected gobshite".
The Independents4Change MEP said the recognition of Mr Guaido as the country's rightful president by more than 50 countries was an "absolute embarrassment".
Mr Guaido, has been recognised as Venezuela's interim president by more than 50 countries - most of them western - following the 2018 elections.
Although the election was won by Nicolas Maduro, the result is disputed over irregularities.
In a remark to the chamber in Strasbourg, Mr Wallace said: "Do you not agree that the recognition of Guaido is an absolute embarrassment to anyone who has to occupy this chamber and it is a disgrace on the part of member states of Europe that so many of them have recognised an unelected gobshite."
The remark was made at a European Parliament meeting about the Venezuelan presidential crisis.
Mr Guaido returned to Venezuela on Tuesday after touring Europe and North America in an effort to rally support. He left Venezuela in January, defying a travel ban.
He was received as Venezuela's head of state in Britain and France and was cheered as a hero by Venezuelan emigres in Spain.
He also met US President Donald Trump, helping demonstrate that he retains the backing of international players.
However he faces an increasingly weary population that in recent months has shown waning enthusiasm for more demonstrations.
Many opposition sympathisers have become frustrated by Mr Maduro's continued grip on power, thanks to backing from the armed forces and support from China and Russia.
Mr Guaido arrived at Maiquetia International Airport outside Caracas to a throng of supporters as well as groups o fpro-government agitators who shouted insults and hit his car with sticks and traffic cones.
ournalists said they were attacked and robbed while covering his return.
The ruling Socialist Party has repeatedly suggested Mr Guaido could be imprisoned for seeking international assistance to end Mr Maduro's rule.
Despite this, the government has never executed an arrest warrant, and Mr Maduro appears willing to allow him to remain free.
"We don't waste time on bozos," Mr Maduro said during a televised broadcast on Tuesday evening, in an apparent reference to Mr Guaido.
Venezuela's economic collapse under Mr Maduro has led nearly 5 million people to emigrate, creating a migration crisis in nearby Latin American nations.