Fiona Onasanya

Dr Christian DeFeo, who managed campaigns and communications for Miss Onasanya, said he was compelled to contact police after spotting a news report of her trial at the Old Bailey.

Dr DeFeo said he discussed with his wife Caroline Earle whether or not to give evidence against the 35-year-old, but decided he had a moral duty to contact police on Tuesday this week, the day Onasanya’s trial began.

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He told the court he had “enormous hopes invested” in the Labour MP, who was elected in 2017, and added: “I never dreamed in my darkest dreams -

I never thought I would have to be sitting here (giving evidence).

“It is with the greatest reluctance I have to do this.

“To do otherwise, I cannot. It’s morally and legally unacceptable not to.”

Fiona Onasanya

The court heard there had been a “bit of a falling out” between the MP and Ms Earle after an event marking 100 years of Labour in Peterborough was cancelled by Onasanya.

Asked by prosecutor David Jeremy QC whether he “had it in” for Onasanya as a result of the dispute, Dr DeFeo said he did not, and added: “From day one I wanted her to succeed.

“I wanted her to be a great MP and I said on a number of occasions that I wanted her to be an MP as long as she wanted to be.

“It’s a terrible thing to have to do this.”

Onasanya is accused of plotting with her brother Festus Onasanya to claim that a Russian man was behind the wheel of her Nissan Micra when it was clocked doing 41mph in a 30mph zone on The Causeway near Thorney in Cambridgeshire.

The incident happened near where Dr DeFeo lived at the time, on July 24 2017, a week after Onasanya was elected MP.

Onasanya, from Peterborough, denies one count of perverting the course of justice.

Her brother has pleaded guilty to three charges of perverting the course of justice, including to one related to the July 24 incident.

The court was told about an email exchange between Onasanya and Dr DeFeo, arranging to meet on July 24 last year.

Asked what time she was there, the witness said: “I cannot say a specific time, however she arrived late and was there quite late because we offered her a bed to stay the night.

“She arrived in her car. She arrived alone. She pulled up her car in front of our house. I greeted her at the door.”

Dr DeFeo said Onasanya, his wife and himself spent no less than two hours discussing the “nitty gritty” of a charity lease in his living room.

They were there together throughout apart from the occasional “loo breaks” and his wife going into the kitchen to prepare a “hot lemon squash”.

Dr DeFeo said Onasanya had been to his home three or four times, including when he threw a “victory party” to celebrate her election, accompanied by her mother.