Marine Le Pen, who firmly believes she is on course to become the next French president, praised the UK's "honourable" Brexit voters who freed Britain from a "huge prison".
France is seen as a key power-broker in the European Union alongside Germany, but Ms Le Pen's warm words may not be welcomed by Prime Minister Theresa May, given the long-standing UK Government policy not to engage with her.
Le Pen criticized the British prime minister for hosting her main rival, centrist Emmanuel Macron, at Downing Street in February, but failing to offer her the same privilege. She also insisted that no British immigrants living in France would face persecution, though she said that French people would have priority when it came to jobs.
She batted away questions about antisemitism within her party, asking to be judged on her reaction to it, instead. "There weren't mass murders as it's been said", Loeuillet reportedly said in the documentary, which is to be aired later Wednesday.
He did not find time to ask her about the numerous legal troubles circling around her campaign, such as the allegations that an adviser illegally funded the FN's campaigning in 2014 and 2015.
Le Pen and Wilders were pictured together in a series of light-hearted selfies in January when they met with other far-right politicians who hope rising anti-establishment sentiment across Europe will give them a lift at the ballot box. She has previously denied the claims.
In an interview with former UK Independence Party (Ukip) leader Nigel Farage on the LBC, she complained of being snubbed by May and questioned her judgement, recalling how May treated US President Donald Trump in a similar manner before he became the president of the United States.
Marine Le Pen made the commitment in a letter to Gaston Flosse, the leader of the Tahoeraa Huiraatira Party which won an overwhelming majority in the last election but has since split and joined the opposition ranks.
In a promotional tweet ahead of the broadcast at 7pm on Wednesday night, LBC called the interview "unmissable".
"When people live on our territory and are not criminals, if they don't dispute our laws, our ways of living, our customs, our values and so on, I see no reason why we should not continue to welcome them in the French style".