She’s made her opening gambit. What’s the chancellor’s long game?

She has already said she will be tough on adhering to rules designed to limit borrowing for day-to-day spending.

Currently, Reeves would need to make some very tough choices, potentially cutting spending on councils, prisons and courts and raising some taxes to do this.

This will come to a head in an autumn Budget and Spending Review.

When pushed on whether she can really deliver a step-change to housebuilding, infrastructure and energy investment, while her government continues cuts to public investment planned by the Conservatives, Reeves is defiant.

“We need the private sector to build homes, we are not going to be in the business of constructing homes ourselves,” she replied,

The more the private sector steps up, the better these difficult trade-offs will get – with more money from outside, the less the government will have to make difficult decisions on spending cuts or tax rises.

Conversely, if the private sector is expected to do not just the heavy lifting but all the lifting on investment to power growth, it gives it strong leverage over policy.

For example, Labour says it will deliver 1.5 million new homes a year, but what will it do if housebuilders ask which construction workers will build such homes?

How will it answer the energy firms saying that regulator Ofgem needs to free up regional pricing of electricity so that Scotland can benefit with cheap or even free energy arising from its surplus wind power?

The question is: what is Reeves prepared to sacrifice in order to meet Labour’s “number one” growth mission?