European Parliament Vice-President Mairead McGuinness has warned that Brexit Party leader Nigel Farage will not stop trying to "destroy" the EU.
Speaking ahead of the UK officially leaving the EU, Ms McGuinness said Mr Farage will continue his campaign to break up the European Union from outside.
"I am afraid Nigel Farage has used the platform of our parliament in Europe to destroy the European Union and that was his ultimate objective," she said.
"He's not going to stop now, he's not retiring, he's going to keep going, not just in the UK but right throughout the European Union," she added.
Ms McGuinness said she was sure Mr Farage did not care if she would miss him or not, before adding: "I don't think we've seen the back of him."
The Fine Gael MEP clashed with former Ukip leader on the UK's final day in the European Parliament.
Ms McGuinness cut off Mr Farage's microphone when he and his colleagues began waving miniature Union Jack flags in the parliament.
The only flag permitted in the chamber is that of the European Union.
Ms McGuinness said she cut off the Brexiteer MEP because he was causing a "circus".
"When you're not in the chamber it can be hard to judge the moment but I have to judge the moment carefully.
"We have a rule in the house that no flags are to be shown except the two behind the podium, and the president insists on that and I'm under orders," she said.
She said some of the other MEPs in Mr Farage's grouping told her they were not impressed with his antics in the parliament.
The UK officially left the EU at 11pm last night. Mr Farage was instrumental in securing a vote for Brexit.