The bulk of the money will go on new specialist services for children and young people, plus extra assistance for people with severe mental illnesses and faster help for those afflicted by depression and anxiety. The extra funding is a response to the impact of the pandemic on mental health. Mr Sunak will vow to make rapid progress on the backlog of adult mental health referrals. Support for NHS workers is also expected.
A service to provide real-time data on suicides will be launched so prevention efforts can be better targeted.
The Treasury claims that poor mental health costs the economy up to £35billion a year.
The Chancellor said: “The pandemic has had a major impact on mental health because of increased isolation and uncertainty. So it is vital we do everything we can to support our mental health services and ensure help is there for people.
“This funding will make sure those who need help get the right support as quickly as possible, so they don’t have to suffer in silence.”
The Government is also announcing a Winter Mental Health Plan.
Wednesday’s announcements will also include the National Infrastructure Strategy – originally expected in March – which will set out the priorities for £100billion of long-term investment.
Alongside action to boost transport connectivity and help achieve net-zero emissions by 2050 there will be £1.6billion to tackle potholes. Funding is also expected for fibre broadband and flood defences.
In a major move, the Treasury will change its “green book” so investment rules are not biased in favour of London and the south east of England.
The Chancellor will confirm a national infrastructure bank – a post-Brexit replacement for the European Investment Bank. Its headquarters will be in the North of England.
The Treasury says the bank will be “key in helping to deliver the Government’s commitment of over £600billion of investment over the next five years”.
Mr Sunak will be braced for controversy. Unions are alarmed at reports he will introduce a cap on public sector pay increases set at or below inflation, although doctors and nurses would be exempt.
Former prime ministers David Cameron and Tony Blair have also warned against reducing the international development budget.
Mr Sunak is expected to cut the commitment to spend 0.7 per cent of national income on overseas aid, to 0.5 per cent. Such a move could save more than £4billion, but Mr Cameron warned any reduction in aid “would be a moral, strategic and political mistake”.
In a newspaper interview this weekend, the Chancellor said his task was to keep the economy going, but he hinted work to balance the books would have to begin next year.
He said: “There is a question of timing. The economy is in difficulty. While that’s happening, the right thing to do is to support the economy, and jobs are my No 1 priority, but – obviously – you can’t sustain borrowing on this level indefinitely.
“Once we get through that, we’ll have to figure out what the best way of returning to sustainable public finances is.
“I’m hopeful that by the spring, with positive news on both mass testing and vaccines, we can start to look forward.”