Former MP Eric Joyce could face jail after being found guilty of attacking two teenagers in an “unjustified and unprovoked” assault in a Chalk Farm shop.

Joyce, the former MP for Falkirk, of Chalcot Square, Primrose Hill, attacked the boys aged 14 and 15 at News & Food Express in Chalk Farm Parade, Adelaide Road, on October 17.

During his trial at Westminster Magistrates’ Court today, the 54-year-old insisted he was performing a “citizen’s arrest” but District Judge John Zani found him guilty of two counts of common assault.

The judge said: “Given my findings and your previous convictions, all options including imprisonment will be considered.”

Prosecutor Jon Swain told the court the former Labour MP attacked the boys after they walked past him as he stood by a drinks fridge.

After an “exchange of words”, Joyce grabbed the 14-year-old and knocked him to the floor, Mr Swain told the court.

Mr Swain said the second boy tried to help his friend but was elbowed by Joyce and winded.

When police arrived, Joyce claimed one of the boys had been aggressive and headbutted him, the court heard.

Joyce’s attacks, which happened at around 9.40pm, were captured on the shop’s CCTV camera.

“It’s the Crown’s case that the actions taken by Mr Joyce constituted an unjustified and unprovoked assault on both boys,” Mr Swain said. “Nothing either did warranted the level of violence demonstrated.”

In the witness box, Joyce - who denied both assaults - insisted he had overcome his battle with alcohol after a string of previous convictions.

The court heard that he was convicted in 2012 of four common assaults in a House of Commons bar - which led to his resignation from the Labour Party - and in 2014 of breaching the peace at Edinburgh Airport.

Joyce, who is not standing for re-election in Falkirk in the general election, claimed he was performing a “citizen’s arrest” when he held the boy down on the floor because the youngster tried to knock over a shelf.

But shopkeeper Ali Fahan told the court: “The boy was crying, saying he wanted to go home. I told the man to let him go because he was crying. The smaller boy was trying to save his friend. He was trying to push the man and save his friend and go home.”

Judge Zani told Joyce: “In my view, you underplayed the violence you meted out to these young men and wanted the police called so as to justify your actions. You readily told police, incorrectly, that [one boy] headbutted you for no reason.”

Joyce was released on conditional bail ahead of sentencing on May 27.

Last night, Joyce’s partner, The Sunday Times columnist India Knight, wrote on Twitter about his trial.

In her first tweet, she wrote: “Goodnight! I shall return when @ericjoyce is let off tomorrow for not taking kindly to being aggressed by, um, ‘excitable’ teenagers.”

She then added: “Don’t intimidate people who might intimidate you back, is the lesson. Especially in a corner shop at 5pm.”