Rachel Reeves’s spending review will be about the departments that have lost out

“It’s a big deal for this government,” says Simon Case.

“It’s the clearest indication yet of what they plan to do between now and the general election, a translation of their manifesto.

“This is where you should expect the Chancellor to say, on behalf of the government: ‘This is what we’re about’.”

As the former cabinet secretary, Mr Case was the man in charge of the civil service during the last spending review, in 2021.

On Wednesday, Rachel Reeves will unveil the Labour government’s priorities for the next three years. But it’s unclear whether it will provide all that much of an answer about what it’s really about.

Unlike the Autumn budget, when the chancellor announced her plans on where to tax and borrow to fund overall levels of spending, the spending review will set out exactly how that money is divided up between the different government departments.

Since the start of the process in December those departments have been bidding for their share of the cash – setting out their proposed budgets in a negotiation which looks set to continue right up to the wire.

This review is being conducted in an usual level of detail, with every single line of spending assessed, according to the chancellor, on whether it represents value for money and meets the government’s priorities. Budget proposals have been scrutinised by so called “challenge panels” of independent experts.

It’s clear that health and defence will be winners in this process given pre-existing commitments to prioritise the NHS – with a boost of up to £30bn expected – and to increase defence spending.

On Sunday morning, the government press release trumpeted an impressive-sounding “£86bn boost” to research and development (R&D), with the Science and Technology Secretary Peter Kyle sent out on the morning media round to celebrate as record levels of investment.