Sajid Javid's polite words with a sting

Not so long ago, Boris Johnson was the one giving a resignation speech from the backbenches when he quit, rather than go along with Theresa May's version of Brexit.

It was a decision that arguably set him on the path to No 10.

Well, just after Prime Minister's Questions, he had to listen to his recently departed chancellor do the same, having quit the government barely three months into its life.

Sajid Javid is not a political trouble maker.

He was an experienced member of the cabinet and a one-time leadership contender himself.

Those close to him and the prime minister contend that the two men maintained decent enough relationships throughout the last couple of bumpy months.

So, while his words were polite in tone in the Commons, they will have stung.

Just a fortnight before the Budget, Mr Javid felt the need to make a very public warning about the dangers of splashing money around.

No 10 feels a political pull to get money out of the door, to spend visibly, and quickly. "Levelling up" is the jargon.

The practical politicians are trying to show the public, particularly those who voted Tory for the first time in areas that used to be hostile to the Conservatives, that they made the right choice.

New MPs have been busy putting selfies of themselves trotting into No 11 Downing Street online this week to show how they are arguing the case for money for their regions.

The prime minister himself is also fond of infrastructure projects, even though some of his wilder dreams remain precisely that - fantasy.

But while the government does want to spend billions, it doesn't want to raise taxes.

The Tories won the election promising to be careful with the country's money and not to start borrowing like crazy.

It doesn't take a chancellor - or a former chancellor - to work out there is a tension in trying to meet those three different goals.

Mr Javid's reminder of the need for Conservatives to be careful with the cash could have been taken from the pages of the most traditional chancellors' manual.

But it matters in this political moment, because there is a new Tory government whose centre cares less for that tradition, but is yet to reveal any magic formula that shows how can you can satisfy the public with high spending and low taxes.

What was a lot more awkward, and left the prime minister trying to avoid squirming on the frontbench, was Mr Javid's attack on the style of government, suggesting that the way it is being run is not good for the country.

The former chancellor cautioned against an over reliance on one person's ideas, stressed the importance of checks and balances, and the ability of ministers to be able to speak truth to power.

He only mentioned the prime minister's chief adviser, with whom he clashed, in an indirect gag about "comings and goings".

But there was no doubt that he was taking aim at Dominic Cummings - the most senior aide in No 10 - respected by devotees for his relentless determination and high standards, but described by critics as arrogant, unrealistic and not quite as clever as he thinks he is.

There are enormously different views around.

Some MPs and officials think it's absolutely right that the government, with a big mandate that promised change, is determined to do things differently.

One senior official told me: "Cummings is tough, but he should be tough.

"There are too many people at the top of the civil service who try to bluster through and he won't have that."

But for others, the government is rattling the cage too hard.

One minister told me yesterday they worried that some of the methods are "lunatic".

Ultimately, however many column inches this all fills now, the government will be judged by the public on what it actually does, rather than Westminster chatter in these early few months.

But it matters today that a prominent politician like Mr Javid was worried enough to sound the alarm as he did today, giving a public face and voice to the many more with private concerns.

Boris Johnson has a huge majority, but he can't count on endless goodwill.