A prison inmate sent a letter threatening to kill Boris Johnson and his girlfriend - days after being charged over vile threats posted to Maidenhead MP Theresa May, saying he would "eat her corpse".

Birmingham Crown Court was told mail sent by Muslim convert Rakeem Malik threatened to car-bomb Labour MP Rosie Cooper and her party colleague Jess Phillips.

Extracts from the letters read into the court record on Thursday revealed that Malik threatened to eat Mrs May's corpse, kill Mr Johnson "by Christmas" and bomb Ms Cooper on behalf of "Jihadis of England."

Malik is serving a life sentence imposed in 1999 for the attempted murder of his "cell-mate" at Merseyside's Ashworth high security hospital, having previously been convicted of possessing an offensive weapon, indecent assault and assault on a police officer.

The 52-year-old, who is being held at HMP Birmingham, pleaded guilty at an earlier hearing to three counts of making threats to kill West Lancashire MP Ms Cooper in May 2019.

He also admitted making a threat to Ms Phillips in November 2019 and sending a letter to her with intent to cause distress in December last year.

Malik, who is said to have a psychopathic sub-type of anti-social personality disorder, also admitted sending two letters with intent to cause distress or anxiety to Mrs May in September 2018, and another to Boris Johnson on the same day as the final letter sent to Ms Phillips.

Opening the facts of the case via Skype link, prosecutor Simon Davis told the court that Ms Cooper was listening in the proceedings.

Mr Davis said Malik, who was born Paul Anthony Harrison, was held at a medium secure psychiatric facility in Birmingham between July 2017 and October 2019.

Describing how the inquiry began, Mr Davis told the court Malik had been identified as the author of three letters sent to Ms Cooper.

He then admitted to sending letters to Mrs May.

Mr Davis told Judge Samantha Crabb: "As one would imagine, letters addressed to the Prime Minister are vetted well in advance of them ever reaching the Prime Minister.

"On the 14th of September 2018, a letter destined for Theresa May was received at the Cabinet Office in London.

"The letter said: 'I'm going to kill you. Jihadis of Britain are going to kill the police at the gates. Then I'm going to kill you and then eat your corpse."

Another letter sent to Mrs May, the MP for Maidenhead, threatened to use an RPG to kill her.

Neither letter addressed to Mrs May was ever delivered to her personally and she was unaware of their content, the court heard.

Malik was arrested in September 2019 and said he had written the letters because he was "fed up of hearing about Theresa May" and wanted to scare her.

It also emerged that an envelope franked in Birmingham was opened at Ms Cooper's office on May 20 last year, which stated: "You will die the same way as Jo Cox."

The letter also made a rape threat towards Ms Cooper, who had previously been the target of a murder plot by a neo-Nazi terrorist.

Further letters sent to Ms Cooper threatened: "Jo Cox was murdered by Thomas Mair and we are going to kill you the same way.

"We've being following you, be ready to die. Nice car you may need to get it checked when you turn it on it may go bang."

The court heard that Ms Cooper had made a witness statement, in which she said she "was angered and disconcerted" by the threats.

Mr Davis told the court: "As a Member of Parliament, she has become familiar with people venting their anger and frustration towards MPs.

"The third letter was most concerning. The threat to put a bomb in her car made her feel very scared.

"In a way these three letters couldn't have come at a worse time. It made her believe the person responsible for writing the letters would have carried out his threats."

Malik was returned to prison in October last year and went on to send a letter to Ms Phillips' constituency office.

Mr Davis said of the Birmignham Yardley MP: "She was opening the mail received from the House of Commons. In it was a letter which appeared to have come from a prison setting."

The letter contained a reference to jihadis and a death threat to the MP and her family.

In a statement read to the court by the prosecutor, Ms Phillips said the threats had left her feeling shocked, upset, alarmed and distressed.

The MP stated: "The murder of Jo Cox, one of my best friends, gives me a certain perspective around the threat to me and my family."

Within days of Malik being charged with six of the offences in December 2019, two further letters sent by him were intercepted in the post room at HMP Birmingham.

One contained further threats to Ms Phillips, while another was addressed to Prime Minister Mr Johnson.

No statement from Mr Johnson was read to the court, which heard that the letter sent to him stated: "I'm going to kill you and your girlfriend. I'm going to blow you both up.

"I'm going to do it by Christmas."

Offering mitigation, defence counsel Andrew Jackson described the letters as "the rantings of a disturbed individual who frankly wallows in attention seeking."

Mr Jackson added: "He is a physical wreck - he is a 52-year-old diabetic with heart disease and asthma.

"He has chronic obstructive pulmonary disease, he is registered blind and he has a bilateral leg amputation.

"Though terrifying as (the offences) undoubtedly were, he is incapable of delivering actual violence."

Malik, who appeared via a prison videolink, will be sentenced on Thursday.