Labour were committed to a fiscal credibility rule in their 2017 manifesto meaning they would balance the deficit in the next Parliament.
If they are keeping this rule then it is inevitable that general taxation (NI, fuel duty, VAT etc) are all going to go up MASSIVELY.
You just cannot pay out £200-£500bn and pay for it with modest tax increases on the rich, impossible. Even tightening taxation on the rich for example by stopping avoidance/evasion will not raise that amount of money.
Of course the other answer is they are going to borrow it (breaks their credibility rule) OR they will print the money instead.
If it's the latter and they print money then their other plans like minimum wage increases, 4 day week etc are completely and totally pointless because of inflation. You then probably have a collapsing £ and interest rate rises which will bankrupt half the country.
This is why Labour are so dangerous.