Someone is trying to set things on fire for the Sunday papers and morning shows. That usually means there is less in it than is being reported.
" The MPs are said to be threatening to vote against the budget this autumn, and to have been pushed into action by Williamson, who was promoted from chief whip to defence secretary by May last November. He is reported to have told senior military leaders: “I made her so I can break her.” "
If I were a suspicious sort of person, I might wonder if this was being leaked precisely so May can be seen to face down Williamson, refuse to squander billions on shooty bangy stuff nobody really cares about, and instead offer more cash tribute to the Great God Skoolzanospitals over the protests of her out-of-touch "nasty party" backbenchers who want to spend money on depleted-uranium baby-seeking missiles instead of NHS management bonuses priority healthcare requirements.
After all, voters claim to be deeply concerned about things like the NHS and schools and policing and social care; while the few who actually care about defence, are going to go... where? I mean, if you're going to withdraw your vote from the Tories in protest at their attitude to the defence of the realm, which Opposition party is offering to do better, spend more and more wisely, reform more boldly? Labour under Corbyn and McDonnell? The Liberal Democrats? The Greens?
For a calculating politician fighting short-term battles, like the PM, this is a no-lose situation. For Williamson it establishes his credentials in the longer game with the party membership (who bear little relationship to the rest of the population) for his leadership bid as The Only Candidate Wot Cares About Our Brave Boys (and girls).
What I very much doubt is that the actual details of defence are much known to, or cared about by, any of the players in this particular game...
edited to add... damn, beaten to it by something saying the same thing more succinctly from @alfred_the_great...