Robert Vidler denied the charges, explaining to the police that he sometimes lent his phone to friends when he was drunk, the Crown Prosecution Service (CPS) said.

Vidler was found guilty of causing harm to parliamentary staff who listened to the voicemail messages he left for both ruling Conservative and opposition Labour MPs.

All six MPs targeted have expressed alarm at Prime Minister Boris Johnson's threat to take Britain out of the EU in October, even if this means leaving without a negotiated agreement with Brussels.

Labour's Brexit spokesman Keir Starmer "was called 'a traitor' and Vidler threatened to kill the MP," the CPS statement said.

Conservative moderate Nicky Morgan was told her days "were numbered," the statement said.

Brexit has inflamed passions across Britain since the country voted to leave the EU by a narrow margin in 2016.

The process has been delayed twice already because parliament refuses to approve the withdrawal terms the sides agreed last year.