Broxtowe MP Anna Soubry cancelled plans to give a speech outside Parliament on Saturday (September 7) morning over fears for her safety.
The leader of the Independent Group for Change political party told Nottinghamshire Live that "extreme right-wing and fascist groups" left her feeling as though she was "not safe".
Members of the March for Change group, which is asking MPs to reject Brexit, had set up a small rally in Parliament Square on Sunday, September 7.
The rally clashed with a demonstration from pro-Brexit group, the Democratic Football Lads Alliance (DFLA), and Ms Soubry said she took the "difficult decision" to leave the area as to avoid perceived provocation from the group.
"It's not a very big rally and there is a counter demonstration from extreme right-wing and fascist groups and I'm afraid I did not feel safe," Ms Soubry said.
"I travelled down this morning by myself and I never thought it would be a problem. I feel bad having to take up the police's time this way.
"These people, who I've encountered before, I think they had already tried to storm the stage and my presence would have worsened the situation.
"It's a really sad day when an MP feels so concerned about their own safety that we cannot even speak outside Parliament.
"This is the situation the country is in. We are in a terrible, terrible situation."
The Press Association reports that some members of the DFLA began to approach members of the March for Change group before throwing a beer can.
Police officers on horseback had to intervene.
"With [Boris Johnson] suspending Parliament and saying that he will not comply with any law, you cannot be surprised that citizens feel they have a right to do this," Ms Soubry told Nottinghamshire Live.
"I'm sorry I have let people down but I had to put my safety first. I've had experiences with these people before, there are a lot of people there wearing those yellow vests.
"It has got worse since that wretched referendum. We know that hate crime in Nottinghamshire has gone up."
