Mr Calver details in the email how he argued with Mr Noorani over the phone, and then how on the same evening he received a number of “sinister calls”.

“At around 8.15pm, I started to receive a series of silent nuisance phone calls on my home phone, the caller withholding their number. These silent calls were interspersed by four more sinister calls," said the email.

“Two of the calls were from a male describing himself as ‘an acid expert from Widnes’ who was going to visit in order to demonstrate the effect of acid on my wife’s face and other parts of her body.

“The fourth call (to my mobile phone) purported to be from Merseyside Fire Brigade and instructed me to vacate the house as it was about to catch fire.”

Mr Calver’s team have alleged that Mr Noorani had asked a 16-year-old to phone Mr Calver and give him a “hard time”.

Miss Cole-Wilson said the boy was known to Mr Noorani as the son of one of his tenants.

She said he had told the police Mr Noorani had asked him to make the call. "But I urge you to treat this statement with the upmost caution," she added.

She said that he was a "troubled" youngster whose mother had died from an overdose and whose father had abused drugs.

She said he had a track record for lying, and what he had told a police officer could not be trusted.

Mr Noorani told the court he had not instigated the malicious phone calls, but had indeed been a victim of threatening phone calls himself in the following months.

Mr Noorani told the court he believed he had been shunned by party members after the email, including Wirral West’s Conservative prospective Parliamentary candidate, Esther McVey.

"I had an appointment with Esther McVey, then I had a message saying 'Sorry, I can't make it'."

Jacob Dean, defending Mr Calver, told Mr Noorani: "My case is that you suffered what you saw to be a series of personal slights, and you made threats to Mr Calver as a result of this through silence calls and instigating abusive phone calls.

"The boy is a smoke screen to divert the jury from the real issues in this case."

This was denied by Mr Noorani.

The case continues.