Keir Starmer has condemned Conservative attacks on him over his comments that he avoids working after 6pm on Fridays to spend time with his family, as the government’s antisemitism tsar called them “dangerous”. The Labour leader was responding after senior Conservatives stepped up criticism of him in interviews and on social media overnight for saying he hoped to preserve family time in Downing Street if he won the general election. Starmer told Virgin Radio on Monday: “We’ve had a strategy in place and we’ll try to keep to it, which is to carve out really protected time for the kids, so on a Friday – I’ve been doing this for years – I will not do a work-related thing after 6 o’clock, pretty well come what may. There are a few exceptions, but that’s what we do.” In response, the Tories launched a social media campaign portraying Rishi Sunak as younger and more energetic than Starmer, and questioning the Labour leader’s commitment to national security. A mocked-up outline of a Labour prime minister’s day suggested Starmer would be “a part-time prime minister”. Speaking on the campaign trail on Tuesday, Starmer said: “They’re just in this negative desperate loop. And it is really desperate. My family’s really important to me as they will be to every single person watching this. And I just think it’s increasing desperation, bordering on hysterical now.” Sunak was pressed repeatedly on whether it was right to criticise Starmer’s work ethic as he toured a warehouse in Banbury, Oxfordshire, where he stood by his ministers’ attacks on the Labour leader but did not repeat the strength of their criticism. “Everyone is going to approach this job in a different way in my experience, there is always work to do,” he said. “There’s always decisions that need to be made. And, you know, that’s what the job requires. And that is what the prime minister’s job means. That’s what public service is about and the sacrifice that entails.” Asked whether it was right for Grant Shapps, the defence secretary, to claim that Starmer might clock off when pressing military decisions needed to taken, Sunak said: “I do worry about our country’s security, as there are deep concerns about it. This is the most dangerous time that our country has lived in it for decades.” Claire Coutinho, the energy secretary, earlier repeated the criticism of Starmer, telling LBC radio it was “unrealistic” of him to aim to finish working at 6pm on Fridays. “I also think it’s a bit odd, because they’re also saying they want to make people in the NHS work overtime and at weekends, so I think to do that on one hand, and on the other hand say that you’re not going to work past 6pm is a bit tin-eared.” However, when she repeated the criticism on Times Radio she said she had not read Starmer’s comments in full. When the Labour leader’s quote was read back to her, she replied: “I think it’s going to be difficult to achieve in government to say: ‘Come what may, I will never do any work.’” The Tories came under fire from those pointing out that Starmer’s wife, Victoria, is Jewish and the family observe traditional Shabbat dinners on Friday nights. The government’s antisemitism adviser, the Labour peer Lord Mann, said: “The attack on Keir Starmer for asserting his right to family time on a Friday night, as he has done for many, many years, is so dangerous. “It’s a very strange thing to attack over. I’m the independent adviser to the prime minister and my advice would be this is not an area to stray into.” Sunak declined to comment on Mann’s criticism. Marie van der Zyl, president of the Board of Deputies of British Jews until earlier this year, said it was “horribly stigmatising” to criticise someone for wanting to spend time with their family and be part of a tradition. “For Jews of all denominations and their loves ones it’s really a sacred time and I think we should be recognising that here is someone who appreciates values and traditions. He’s setting a good example and for that to become something that is criticised, I think, is grossly unfair.” Van der Zyl has recently become a Labour party member. The shadow health secretary, Wes Streeting, asked on Tuesday if he would work beyond 6pm on a Friday, said: “I’m sure I will be and I’m sure Keir will be doing so too.” He told Times Radio: “The attacks on him are a total disgrace and it shows how far these people have fallen, how heavily they’re scraping the barrel and why they need to be removed from office on Thursday.”