A Labour MP who dreamed of becoming Britain’s first black prime minister could be jailed after she was convicted at the Old Bailey of lying to the police about a speeding charge.

Fiona Onasanya, a former party whip, was found to have colluded with her brother Festus after she was caught speeding just weeks after being elected as an MP in last year's election.

During her retrial, called after a previous jury failed to reach a verdict, the court heard that the 35-year-old had been texting as well as speeding but had “persistently and deliberately” lied to police to avoid prosecution.

The verdict now threatens to bring an end to Ms Onasanya’s short-lived political career, with Labour confirming that it had suspended the whip and expected her to resign in order for a by-election to be held in her Peterborough constituency.

Under the law, Ms Onasanya would have to quit if she is sentenced to more than one year in prison, although Labour insiders claimed that she may delay stepping down until sentencing.