Sir Keir Starmer has suggested he accepted £20,000 in donations for accommodation because his son needed somewhere to revise for his GCSEs while his family home was besieged by journalists during the election campaign.

The Prime Minister defended his decision to take gifts from Labour peer Lord Alli amid criticism of the arrangement, saying he was “not going to apologise for not doing anything wrong” and the freebies did not “cost the taxpayer a penny”.

But Sir Keir signalled he could continue to accept hospitality from donors, saying that it was a matter of “judgment” for individual MPs whether they receive certain kinds of donations.

In a series of broadcast interviews following his speech to the Labour Party annual conference, he also said the transition to Downing Street had been “really difficult” for his two children, who were previously raised in North London.

Asked about the donations, Sir Keir said that around £20,000 he had declared from Lord Alli for unspecified accommodation was for his teenager to study for exams in a “peaceful” atmosphere while the then-Labour leader was overwhelmed with media attention in the run-up to the election.

“My boy, 16, was in the middle of his GCSEs. I made him a promise, a promise that he would be able to get to his school, do his exams, without being disturbed,” he told BBC Radio 4’s Today programme.

“We have lots of journalists outside our house where we live and I’m not complaining about that, that’s fine.

“But if you’re a 16-year-old trying to do your GCSEs and it’s your one chance in life – I promised him we would move somewhere, get out of the house and go somewhere where he could be peacefully studying.

“Somebody then offered me accommodation where we could do that. I took that up and it was the right thing to do.”

Asked whether he would like to apologise for the row, he told LBC: “I’m not going to apologise for not doing anything wrong.”

The Prime Minister also opened up about life inside Number 10 following Labour’s takeover in July.

“It has been tough for the kids. I’m not pleading a special case but they’re 16 and 13,” he said. “That’s a very important time.”

The row over declarations by MPs and senior ministers had threatened to overshadow the Labour conference, with criticism aimed at both the PM and his ministers for accepting luxury gifts from wealthy donors while announcing cuts to the winter fuel allowance.

Sir Keir has said ministers will no longer take donations for clothing now they are in Government, but left the door open to receiving more access to events, such as the £4,000 worth of tickets to a Taylor Swift concert he accepted from the Premier League.

Asked whether he would rule out accepting such gifts in the future, he told ITV’s Good Morning Britain: “I think that’s a matter of judgment. There has to be good reason.”