A painter and decorator who told former Labour leader Ed Miliband “I am going to slit your throat” has been jailed for three years.

Michael Donaldson, 56, had pleaded guilty to making a threat to kill after making the remarks to Doncaster North MP Mr Miliband, and two members of his staff, during a constituency visit in Bentley, South Yorkshire, on March 22.

The Recorder of Sheffield, Judge Jeremy Richardson KC, sentencing at Sheffield Crown Court on Thursday, referenced other recent attacks and threats towards MPs, including the murders of Jo Cox and Sir David Amess.

He told Donaldson: “To make a threat to kill an MP is not only a serious matter for that individual, it is a form of attack on parliamentary democracy in this country.

“It undermines the rights of the public to have access to their MP because of the enhanced necessity for security.

“It makes the life of a politician very unpleasant and difficult.

“Politicians are used to the rough and tumble of political life.

“An attack of the kind you perpetrated had nothing to do with legitimate political discourse or political criticism, it was a serious crime and you must be punished for it.”

Mr Miliband and his staff locked themselves inside a charity’s building on Askern Road after Donaldson got about five metres away and was waving his arms about and walking in front of traffic, the court heard.

Donaldson, who told police he had drunk about one litre of vodka, said: “Oh you’re Ed Miliband, I am going to slit your throat, I am going to slit your f****** throat, I am going to do it now.”

A member of Mr Miliband’s staff also saw Donaldson fumbling in his pocket, though he did not have a weapon on him.

Mr Miliband said in his witness statement that he felt “intimidated” and that one of his staff was clearly shaken.

Another member of staff who was present described Donaldson’s behaviour and words as “terrifying”.

During a police interview on the same day, Donaldson told officers “it was only a joke”, despite later saying: “Ed Miliband, he will be in a body bag when I see him next.”

Donaldson has relevant previous convictions for threatening behaviour, affray, crimes associated with alcohol abuse and consumption, and racially aggravated harassment, the court heard.

Judge Richardson added: “Let there be no misunderstanding, to threaten to kill a member of Parliament is a very serious manifestation of this crime.

“Those who perpetrate this crime must expect, and will receive, severe punishment from the courts of this country.

“I repeat, it must be made clear beyond doubt that individuals who threaten to kill members of Parliament must expect, and will receive, severe sentences.”

Donaldson, of Askern Road, was also given an eight-year restraining order against Mr Miliband.

Shaun Sigamoney, of the Crown Prosecution Service (CPS), said: “Michael Donaldson threatened Mr Miliband, despite his effort to play down the incident as a joke or drunken foolishness.

“His actions have no place in a civilised society. Neither Mr Miliband nor his members of staff should have been subjected to such vitriol, it is completely unacceptable.

“Members of Parliament play a vital role in our democracy, those who engage in this criminal behaviour will face the consequences of their actions.”