Keir Starmer has admitted he “made a mistake” in a response to Boris Johnson at prime minister’s questions during a tense clash over Starmer’s previous comments on the European Medicines Agency. Labour rubbished claims from a Conservative MP that Starmer had challenged Johnson in the corridor after their debate in the House of Commons. Johnson has previously accused Starmer of wanting to take part in the EU’s vaccine procurement programme, a charge the Labour leader has fiercely denied, accusing the prime minister of being misleading. However, after a clash at PMQs on Wednesday, Starmer’s spokesperson issued an unusual apology from the Labour leader for a misunderstanding, though reiterating that the prime minister had previously been misleading. “On a number of occasions the prime minister has wrongly claimed that Labour wanted to join the EU’s vaccine programme,” Starmer’s spokesperson said. “That is inaccurate and the claim has been found to be untrue. “This afternoon during prime minister’s questions, Keir misheard the prime minister and assumed he was making the same false accusation again. Keir accepts that on this occasion the prime minister was referring to old comments about the European Medicines Agency, and Keir admits he was wrong and made a mistake in his response.” She added: “It’s not Labour policy to join either the European Medicines Agency or the EU vaccine programme. We have never called for the UK to be in the EU vaccine programme. We remain committed to working with the government to ensure we can be the first in the world to roll out the vaccine.” The Conservative MP Mark Francois, who made a point of order after PMQs reading out some pre-prepared comments quoting Starmer on the EMA, later claimed he had seen Starmer angrily confront Johnson in the lobbies after their exchange. The Labour MP Chris Matheson, who was with Starmer, said the description was untrue. “It’s absolute bollocks,” he said. “There was a brief chat and then Keir and I left together. Nothing more to it than that.” A Labour source: “They had a perfectly reasonable conversation, as they often do after PMQs.” During PMQs Johnson also faced an awkward moment where he defended visiting a Scottish vaccine plant despite a coronavirus outbreak at the site, saying “no one is going to stop me” visiting all parts of the UK. The prime minister was criticised by Scottish leaders including the first minister, Nicola Sturgeon, for his trip to Scotland last week at a time when only essential travel was permitted. The Daily Record reported that Johnson’s visit to the Valneva factory took place 24 hours after a public health investigation that found 14 coronavirus cases – about one in eight of the workforce. Valneva’s chief financial officer, David Lawrence, said Downing Street had been informed before the trip. Responding to the Scottish National party’s Westminster leader, Ian Blackford, in the Commons, Johnson denied any knowledge of the issue. Blackford said it was an “absolutely shocking error of judgment. Anyone can see that his campaign trip to Scotland was utterly, utterly reckless.” Blackford said No 10 had made a choice to proceed with the visit. “They knew the visit posed a risk … the prime minister put politics before public health. Why be so reckless?” Johnson said he had not been made aware of the outbreak “before or since” the visit to Valneva. “It is my job to visit every part of this country, nothing and no one is going to is going to stop me, and I am very, very proud of the record of the government in rolling out the vaccine,” he said.