Keir Starmer will self-isolate after one of his children tested positive for Covid, hours after the Labour leader appeared in the House of Commons for prime minister’s questions.

The Commons Speaker Lindsay Hoyle is understood to be concerned about the growing number of people being forced into isolation, and told colleagues he hopes that the final day parliament sits on Thursday will be as quiet as possible, with MPs attending remotely.

Starmer, who has spent the day in Westminster, where restrictions have been significantly eased, tested negative on Wednesday morning, a Labour spokesperson said.

A spokesperson for Starmer said: “One of Keir’s children tested positive for Covid this lunchtime. In line with the rules, Keir and his family will now be self-isolating.

“Keir was already doing daily tests and tested negative this morning. He will continue to take daily tests.”

Starmer is the latest high-profile politician to self-isolate in the week all restrictions on social contact were lifted in England.

Boris Johnson conducted PMQs by video link because he was self-isolating in his country residence, Chequers.

Johnson and the chancellor, Rishi Sunak, were forced into self-isolation after the health secretary, Sajid Javid, tested positive for Covid just weeks into the job.

It will be the fourth time Starmer has been forced to self-isolate due to a close contact with Covid – and will disrupt plans by the Labour leader to tour the country this summer as he looks to capitalise on the party’s recent byelection win in Batley and Spen.

Starmer was due to launch a “safer communities” campaign on tackling crime and antisocial behaviour on Thursday in the West Midlands.

PMQs had been set to return to normal this week with a full chamber of MPs, none of whom were required to wear masks, but plans were disrupted by the prime minister’s isolation and Hoyle calling on MPs to exercise restraint.

More MPs were in the chamber than when social distancing rules had been imposed, with a number of MPs not wearing face coverings, including the leader of the House of Commons, Jacob Rees-Mogg, and the chief whip, Mark Spencer.

Hoyle had previously urged MPs to be cautious for the last remaining days before summer recess, citing outbreaks in Westminster.

“I really want us to behave safely, responsibly, during these few days. None of us wants to risk taking Covid back to our families, staff or constituents and I’m sure we will want everyone working on the estate to feel safe and secure.”