Annunziata Rees-Mogg says she has "no shame" about taking part in a protest at the European Parliament this morning.
Ms Rees-Mogg was one of 29 Brexit Party MEPs who turned their backs as the EU's anthem Ode To Joy was played by an orchestra.
"I have no shame about having done that. I think it is perfectly fair to stand up and make your point clear on behalf of the British people," she told talkRADIO's Ian Collins.
"We were told to stand up for a country's anthem - our objection was that the EU is not a country. If it is a country, it has no people, no voters and certainly no democracy."
The East Midlands MEP continued: "Changing the entire legal status of the EU from a collection of nation states into a nation state itself was fundamentally insulting to all the voters who have only just put us, there despite the fact we should have left on March 29."
However, Ms Rees-Mogg said her daughter "won't be able to watch" footage of the protest because of Liberal Democrat MEPs wearing bright yellow "b*****ks to Brexit" t-shirts in their own, separate protest.
Defending the action, Lib Dem MEP for the West Midlands, Phil Bennion, said he was told it "wasn't a watershed word".
"I think we probably have lost a bit of decorum, but I think sometimes politics could do with a little bit of lightening up," he added.
"'Stop Brexit' on the front was the key message. That’s what was facing the chair in the Parliament."