The Labour MP Fiona Onasanya has pleaded not guilty to perverting the course of justice, after she was charged with allegedly blaming another driver for a speeding offence.

At the Old Bailey in London, the MP for Peterborough spoke only to give a plea of not guilty. A trial date has been set for 12 November.

Onasanya, a Labour party whip, was elected in June 2017, defeating the Conservative incumbent Stewart Jackson, who became David Davis’s chief of staff at the Department for Exiting the EU until the Brexit secretary resigned last month. The seat now has a majority of just 607 votes.

She is charged, jointly with her brother Festus, with the alleged offence in Cambridgeshire in July 2017. He is also charged with two further counts of perverting the course of justice, in Cambridgeshire in June and in August 2017, and pleaded not guilty to all three charges.

The Labour party said it would not be appropriate to comment on the case. Onasanya, who is a former solicitor, said she would be contesting the case when the details came to light last month. She tweeted: “I will be robustly defending all these allegations, and strongly refute any suggestions that I have broken the law.”