Three men have admitted being involved in a late-night assault on Guardian journalist Owen Jones outside a pub in Islington, north London.

At a short plea hearing on Wednesday afternoon at Snaresbrook crown court, James Healy, 39, from Portsmouth, Liam Tracey, 34, from Camden, London; and Charlie Ambrose, 29, from Brighton, all pleaded guilty to affray.

Healy admitted a further charge of assault occasioning actual bodily harm. He denies the attack was motivated by homophobia and will now face a trial of issue in front of a judge to decide whether that was the case.

The three men face the possibility of custodial sentences following the attack on the journalist and political activist in the summer.

Jones, 35, said he had been celebrating his birthday with friends when he was attacked at about 2am outside the Lexington public house in Islington, north London, on 17 August.

At the time of the incident, Jones has said he believes he was targeted because of his anti-fascist politics and warned that divisive rhetoric is emboldening some on the far right to become violent.

The writer and activist said he was leaving a bar near King’s Cross at around 2am when a group of men “charged out of the pub with military precision” and hit him from behind while he was saying goodbye to friends.

“They kicked me in the back, I was knocked down, then they kicked me in the head and back,” Jones said at the time. Some of his friends were also hurt. “Three of them were punched, my partner was punched … They were only trying to defend me.”

At a previous hearing at Highbury magistrates court, prosecutors said Jones had been subject to a group attack and that this meant it would be calling for a sentence of the highest end of the range for the offences, which was one and a half years.

The defendants have previously argued they didn’t know who Owen Jones was. Their lawyer said that statements previously given by the three had said they were “acting in self defence and defending one another”.