Stanley Johnson, who voted to remain in the EU in the 2016 Brexit referendum but has since changed his mind, told the French radio station RTL that he was "already French" and claiming what was rightfully his.
Johnson told the station his grandmother was French and his mother was born in France.
"I will always be European, that's for sure, said Johnson. "You can't say to the English 'you are not Europeans.' Having a link with the European Union is important."
The 80-year-old previously worked as a member of the European Parliament. However, in an interview with The Times newspaper last December, Johnson said he had changed his mind since the referendum result and was now in favor of leaving.
UK lawmakers on Wednesday approved a post-Brexit trade deal as the EU-UK transition period comes to an end on January 1. When Britain leaves the EU's Single Market and Customs Union, Britons will lose the automatic right to live and work in the bloc.