Two resignation statements, one after the other, gave lunchtime a double-barrelled blast. CRUMP CRUMP! John Healey’s speech was followed by one from his former underling at Defence, Al ‘Killer’ Carns. He’s the one who was in the Special Boat Service before becoming a Labour MP.

‘Killer’ addressed the House as if it were a parade ground: short sentences, an abrupt tone, oratory by numbers. Military bods like to break an argument into constituent parts, the better to din it into squaddies’ skulls.

Mr Healey’s was the more subtle, regretful and therefore deadly attack. It scored a direct hit on Rachel Reeves. Our enemies, said Mr Healey, ‘don’t follow timetables set by the Treasury’.

The Chancellor was not present but quite a few other Labour MPs were, and plenty nodded in agreement. Ms Reeves is not much loved on the Labour benches.

The bombardment started at 1.45pm. Mr Healey began by saying he was ‘a proud parliamentarian’ who had resisted commenting before he could tell the Commons why he quit. This may have sounded like sucking-up to Mr Speaker (who goes tonto when the Commons is bypassed) but it had wider significance. Here was someone who resigned from the Cabinet on the most serious policy matter possible. If Labour is ever to be persuaded to spend more on Defence, the people who need persuading are its MPs. Mr Healey was not just criticising the Treasury. He was telling his comrades to grow up.

The chamber was full enough to establish critical mass. More MPs arrived as the speech continued. Mr Healey stood beyond the gangway, third row back, doughnutted by admirers. The Government’s deputy chief whip, Sir Mark Tami, stood near the Serjeant at Arm and listened with apparent benevolence. Ditto Wes Streeting. Ditto Luke Pollard, still a Defence minister. Mr Pollard was at the despatch box only on Monday defending the Government’s Defence policy. Now here he was showing support for his old boss as he blew that policy to smithereens.

Jon Pearce, one of Sir Keir Starmer’s parliamentary private secretaries, draped himself over a bench at the far end of the House. He looked exhausted.

‘My decision was about country, not career,’ said Mr Healey. That ‘career’ could easily have been misheard as ‘Keir’. And yet Mr Healey initially coughed up praise for Sir Keir. A Mark Antony touch. That done, he said this was ‘the age of hard power and rising threat – not the moment for calibration or incremental change’. Incremental change is Labour code for ‘that hesitant nincompoop Starmer’. Mr Healey continued: ‘This means bigger politics, bolder priorities, harder choices.’ Translation: stop blowing billions on welfare.

Another surviving Defence minister, Louise Jones, listened from a discreet spot behind the Speaker’s Chair. Alex McIntyre (Lab, Gloucester) nodded emphatically as Mr Healey spoke. A ministerial aide, Alex Pakes (Lab, Peterborough), chewed gum nervously. Various women sitting nearby cooed and ahh-ed when Mr Healey mentioned his wife. He and Jackie were such solid Labour people that they had met at a trade union conference and were engaged two weeks later. ‘You quick worker!’ said someone from the bench in front. The affectionate laughter this won helped lend the speech extra wallop.

Mr Carns’s speech was a colder affair. Sarah Owen (Lab, Luton N) curled her lip a little. She spoke out of the side of her mouth to Alex Sobel (Lab, Leeds C), who looked no warmer. Peter Swallow (Lab, Bracknell) stared at his mobile telephone. Mr Carns spoke vividly of how drones have changed warfare. What would it take, he asked in exasperation, for these new truths to be believed by Whitehall? But his speech was possibly a little too pleased with itself. And he used ‘kilometres’. Ugh.

As the session ended, Killer Carns dashed off, possibly to drill some more recruits. Mr Healey stayed put, absorbing tributes from colleagues who wished to touch the hem of his robes and say how much they, too, thought Rachel Reeves a dangerous idiot.