PMQs sketch: Starmer turns up heat on Sunak over concrete (though ceiling doesn’t quite cave in on PM)

On what may be the warmest day of the year, Sir Keir Starmer mercilessly turned up the political heat on Rishi Sunak over the schools concrete crisis at their first post-summer PMQs clash on Wednesday.

Following an August recess dominated by self-inflicted blows, including over the small boats issue, the Prime Minister was hoping to claw back ground for the Conservatives exactly a year on since Liz Truss began her calamitous tenure.

Instead the former Chancellor is on the rack because of RAAC - reinforced autoclaved aerated concrete, which has vaulted from little-noticed warnings in structural engineering journals to dominating the national conversation.

Sir Keir likened the Tories to cowboy builders. “The difference is that in this case, the cowboys are running the country,” he said, portraying the privately educated, very wealthy Mr Sunak as out of touch and uncaring.

“He won’t lift a finger when it comes to protecting other people’s schools, other people’s safety, other people’s children.”

The details-oriented PM took refuge in budget numbers for cash and percentage increases, claiming that spending on rebuilding schools was the highest in a decade, and accused “Captain Hindsight” Sir Keir of “opportunism” and jumping on a “political bandwagon”.

Leaping on Labour’s problems in Britain’s second-biggest city, he added: “They bankrupted Birmingham. We can’t let them bankrupt Britain.”

But Mr Sunak hasn’t entirely been helped by Education Secretary Gillian Keegan, who stayed on holiday at the end of August when RAAC in schools emerged as a critical safety issue - and then swore on TV in frustration for not getting more thanks for her response.

Her outburst drew scorn from Sir Keir and other MPs including SNP Westminster leader Stephen Flynn.

But by turning the air blue, Ms Keegan did divert attention this week - for a short while - from Mr Sunak’s own response when he was Chancellor and slashed funding on schools rebuilding.

Hospitals, courts and prisons are all also feared to contain the cheap concrete, which we now know is liable to sudden collapse. The Houses of Parliament are not immune: “Routine ongoing in-house investigations are currently taking place as to whether any parts of the Parliamentary Estate have RAAC,” a spokesperson said.

The House of Commons roof didn’t fall on Mr Sunak’s head at PMQs, but Sir Keir was unrelenting as he probed at the Prime Minister’s vulnerability with thousands of children forced into temporary classrooms.

Sat with a revamped shadow cabinet in the buildup to an election next year, the Labour leader’s thrusts emulated his party’s sharper attack lines this week on social media.

Ms Keegan has been ridiculed for tweeting a graphic saying “most schools unaffected” by the RAAC crisis. Labour’s response went viral, saying “most beachgoers not eaten by big shark”.

That was a reference to the mayor’s irresponsible approach in the movie Jaws - which back in 1975 emerged as the first summer blockbuster. If Mr Sunak thought it was safe to get back in the political water after this summer, events are threatening to show his Government as becalmed at best, and rudderless at worst.