A man accused of assaulting the Guardian columnist Owen Jones because of hostility to his leftwing politics and homosexuality told a court that a collection of memorabilia found at his home was “connected to football and football violence” but did not reflect far-right political views.

The items found at the home of James Healy included pin badges with the names, logos or mottos of the far-right group Combat 18 and the banned loyalist group the Loyalist Volunteer Force, and a black flag featuring a “totenkopf” skull-and-cross symbol and the initials of a Chelsea football hooligan group.

Healy told the court “I didn’t understand their meanings as respects the far right” and said he had collected the memorabilia about 20 years ago in connection with his involvement in the Chelsea Youth Firm, a hooligan group connected with the west London club at the time.

The 40-year-old has pleaded guilty to assaulting Jones last August outside the Lexington pub in King’s Cross, north London, at about 2am but is on trial in front of a judge to determine whether his actions were motivated by homophobia or hostility to Jones’s leftwing political views.

In evidence given before lunchtime on Friday, Healy denied holding far-right views or being a Nazi sympathiser. When asked if he had any anti-gay views he said: “No, not at all. It’s 2020, if you know what I mean.”

He acknowledged that he had a violent past and had previous convictions relating to football hooliganism, but told the court he was no longer involved. “Prior to 2012, when I went to football matches it was with the intention to fight,” he said.

Healy said he had retained the insignia and memorabilia because “I’m a hoarder” and said that he would never have worn any of the pin badges cited by the prosecution after 2001.

He also denied that a photograph of him taken nearly 20 years ago showed him making a Nazi salute, saying that his arm was in fact outstretched to his side to show off a Chelsea tattoo. “I’m showing a tattoo of my right arm, and I’ve got my arm out,” he said.

The 40-year-old’s defence is that Jones had bumped into him shortly before 1.30am inside the crowded pub and that he had spilled his drink and failed to apologise. The court was shown CCTV footage of the pub, although it was impossible to make out Healy or any incident clearly.

Earlier, giving his own evidence, Jones told Snaresbrook crown court that he had no recollection of any hostility directed at him inside the pub.

Matthew Radstone, Healy’s counsel, said to Jones: “You bumped into him with a drink in his hand,” prompting the journalist to respond: “That definitely did not happen.” He added subsequently that “nothing bad or hostile at all” happened inside the pub, where he was celebrating his 35th birthday.

Jones said he did not recognise Healy – “I have no recollection of his face in that pub or at any other time in my life” – and had a different memory of the encounter. Although he had been drinking since 7.45pm, Jones said he was “completely in control” and that he remembered an apparently jovial or friendly interaction.

According to a witness statement from Jones, read out in court, the journalist had a conversation along the lines of: “‘Are you Owen Jones? We are big fans for your work, keep it up,’” which the writer said was typical of many interactions he had had when going out. Jones believes Healy and others may have used that encounter to identify him.

A few minutes later, as Jones and a group of friends were leaving the pub, he told the court he was attacked from behind. “I was saying goodbye to a friend, then I was on the floor, unaware of what was happening, completely disorientated. I hurt my head and I think there was a period of 10 seconds where I don’t really remember what happened.”

Jones said he had become increasingly targeted by far-right activists from December 2018, because of his anti-fascist and anti-racist beliefs, both online and particularly when broadcasting around parliament. He told the court that in late spring the Guardian had hired a security agency “because they were concerned about the rising threat to my person”.

Healy is one of three men who have admitted being involved in the incident. He and Liam Tracey, 34, from Camden, north London, and Charlie Ambrose, 29, from Brighton, all pleaded guilty to affray last month. Healy also admitted a further charge of assault occasioning actual bodily harm.

The case continues.