Boris Johnson’s new cabinet has met for the first time, assembling without masks in a packed room, as the prime minister delivered what he termed a “half-time pep talk” to his revamped team.

Photos of the meeting showed at least 30 people crammed shoulder-to-shoulder in the cabinet room, including aides and officials, none of them wearing masks, and with the windows apparently closed.

Similar images of the last meeting of Johnson’s pre-reshuffle cabinet, on Tuesday, prompted criticism from Labour and others, given government advice suggests people “wear a face covering in crowded and enclosed settings”, particularly if people are with those they do not normally meet.

At Friday’s meeting, Johnson was flanked by Rishi Sunak, the chancellor, and Simon Case, the cabinet secretary. Sitting opposite was Dominic Raab, who was demoted from foreign secretary to justice secretary, but was also officially made deputy prime minister.

According to the handful of media allowed in for the start of the meeting, Johnson appeared jovial, while telling his new lineup they had to deliver.

“To mix my metaphors, this is, if you like, the half-time pep talk,” Johnson said. “This is the moment when we spit out the orange peel, we adjust our gumshields and our scrum caps.

“We get out on to the pitch in the knowledge that we’re going to have to do it together and we’re going to have to do it as a team.”

In another convoluted metaphor, Johnson said he was “thinking about delivery”, making a pun about pregnancy – his wife, Carrie, is pregnant with their second child together.

I’ve seen a few delivery rooms, probably seen as many delivery rooms as anybody in this … with the possible exception of Jacob [Rees-Mogg, the Commons leader, who has six children],” said Johnson.

“I know that delivery normally involves a superhuman effort by at least one person in the room. But there are plenty of other people in that room who are absolutely indispensable to that successful outcome.”

Johnson has at least six children of his own but refuses to discuss how many he has in total.

In the unexpectedly brutal and extensive reshuffle, which began on Wednesday, the former international trade secretary Liz Truss replaced Raab as foreign secretary, and a series of cabinet ministers were sacked.

Among those now absent were the former education secretary Gavin Williamson, the communities secretary Robert Jenrick, and Robert Buckland, who was sacked as justice minister to make room for Raab.