A second man has been arrested in connection with a series of arson attacks allegedly targeting the Prime Minister. The 26-year-old was arrested around 1.45pm on Saturday at Luton Airport on suspicion of conspiracy to commit arson with intent to endanger life. The arrest was made by counter-terrorism officers from the Eastern Region Special Operations Unit. The man has been taken into police custody in London. It came after two properties and a car linked to Sir Keir Starmer were torched in suspected firebomb attacks between May 8 and 12. The first incident occurred in the early hours of Thursday morning last week when a Toyota Rav 4, which used to belong to Sir Keir but had been sold to a neighbour following the general election, was damaged in a fire. Two days later, a flat in Islington that he used to own in the 1990s was allegedly targeted. Then, in the early hours of Monday morning, the Prime Minister's family home in Tufnell Park, which is rented out to his sister-in-law, was set alight. While nobody was hurt at the property, the front door and entrance area were damaged. Counter-terror police began investigating a number of potential motives, including whether a hostile state was behind the attacks. Separately, Roman Lavrynovych, 21, of Sydenham, south London, was charged and appeared in court earlier this week in connection with three counts of arson with intent to endanger life. Mr Lavrynovych was remanded in custody after a Westminster Magistrates' Court hearing. The court was told he lived with his grandmother and was asleep at their property when police raided it in the early hours of Tuesday morning. Speaking in the House of Commons on Wednesday, Sir Keir told MPs that attacks against politicians were an attack on democracy. Mr Lavrynovych's father said that, while his son was a proud Ukrainian, he had always admired the UK. Mykola Lavrynovych, 48, added: "Roman came to London for the first time when he was 10 years old. He spent a year, as his mother was working there. "He went to a British school and studied there for one year. When the invasion started, he left Ukraine for Germany, but after a year he moved to London, which he really liked and wanted to stay there." His father went on: "He has an uncle who is fighting on the front line against the Russians and he is 100 per cent pro-Ukrainian. He has never spoken Russian and doesn't allow his sister and brother or anybody else even to listen to Russian music." Roman Lavrynovych was initially living with his mother and younger siblings but when his sister was unable to get a school place in London, she returned to Ukraine and he remained, living with his grandmother. He set up a building company but had also signed with a modelling agency and is a regular at a local gym in Sydenham, south London. Photographs of him on social media show him doing press-ups in his bedroom. His father said Roman had been happy and settled in the UK and had a girlfriend who was also Ukrainian. He added that he had spoken to him on the telephone just hours before his arrest. Roman Lavrynovych was arrested in the early hours of Tuesday morning. Appearing before Westminster magistrates on Friday morning, he spoke only to confirm his name and date of birth via a Ukrainian interpreter, with his lawyer saying his English was "very limited". Broaden your horizons with award-winning British journalism. Try The Telegraph free for 1 month with unlimited access to our award-winning website, exclusive app, money-saving offers and more.