Donald Macintyre's Sketch: Defence committee fires warning shot across George Osborne's bow

Labour’s Dai Havard was congratulated on all sides for his “extraordinary insights” into the challenges facing the armed forces and for having set them out “very clearly”. The last tribute seemed doubtful.

“The mechanism [keeping defence spending to a minimum of 2 per cent of GDP] would have to test itself against all others,” Havard declared. “Everything would be in a process of iterative, continual assessment… These processes have to be iterative; they cannot be linear, they are not binary and they will not be spasmodic.”

Hmmm. But then this stuff is not for laymen. It is for experts who presumably understand it. And this was a debate attended largely by experts. Which was a pity; you felt something quite big was being described. As Labour’s Gisela Stuart said, Britain risked, for better or worse, becoming one of what the Pentagon once described as its “no-good crummy allies”.

The Defence Committee chairman, Tory Rory Stewart, argued the 2 per cent minimum – which neither main party leader has promised to stick to, despite David Cameron urging the rest of Nato to – was essential because old assumptions “no longer hold” due to Russian aggression and threats out of failed states.

He added: “People stand up and list all the different bits of kit that we have bought.” (Which is what the PM says when challenged). “But they do not intend ever to use it. They are freeloading on the idea that Britain will never act alone.”

Malcolm Rifkind, looking a little more gaunt for his first big speech since the “cash for access” fracas, was eloquent in quoting Frederick the Great’s warning that “diplomacy without arms is like music without instruments”. And that politicians should not be asking the “facile question ‘does this win votes?’”, adding that governments should “occasionally” “lead public opinion.” Was he thinking of George Osborne, credited with warning the PM that the 2 per cent minimum might have to go?

Most ominously for a hung parliament in which his party’s leverage could increase, the DUP’s Jeffrey Donaldson warned that “we will only support a government “which sticks to the 2 per cent”.

Osborne and Michael Fallon were not present. But you can bet the Defence Secretary will be urging the Chancellor to read today’s Hansard before the Tories publish their manifesto.