Do parties know the budget they're working with?

[cointos]

Like a lot of people, I'm struggling with who to vote for. So I tried the vote for policies website and a lot of policies seem perfectly acceptable but how many are realistic? They propose to increase spending on pretty much everything and the one that's made me stop and ask is this:

An additional £8bn for the NHS in England in year one, rising to a total of £28bn in 2030, plus at least £20bn more over the next five years

Don't get me wrong, a lot of them are talking funding increases in the billions but where is it coming from? Do the parties who are NOT in charge of the current budget know the amounts they have to work with? Have they actually worked out where the money is coming from or is it just pie in the sky?

No, no other party has a proper idea of the books.

I am sure someone from Labour, possibly Rachel Reeves, has come out and said the Tories have stopped showing them the opposition the books. They last saw them 2-3 years ago.

However the Tories under Rishi Sunak have shared national security issues with Keir Starmer. So when The Tory campaign was saying Starmer and Labour were a threat to national security it was a complete and utter lie.

Thank @Reugny you've confirmed what I suspected but feared! How ridiculous of us to try to vote based on policies that probably can't be followed through.