Conservative MP John Redwood has claimed that protesters outside of Parliament are making "democractic conversation very difficult".
The MP, who is a member of the Leave Means Leave campaign group, appeared on the breakfast show to discuss a viral video which showed protesters closely following the pro-Remain Conservative MP Anna Soubry and calling her a "Nazi".
Scotland Yard later confirmed it had opened an investigation into whether any offences had been committed by the protesters, following pressure from Parliamentarians urging the Met Police to do more to protect MPs.
Protesters confront Anna Soubry in Westminster. Image: Femi Oluwole
"I find it a very difficult balance to get right - I'm a democrat and I want people to express their views, but I do think some people outside Parliament now cross the line," Mr Redwood told talkRADIO's Julia Hartley-Brewer.
"Your colleagues interview people like myself on the green outside [Parliament], and quite often protesters deliberately try and prevent the audience hearing what we're saying."
He added: "I think it is very undemocratic. Surely in a democracy both sides make their case and the public make their decision."