I don’t know the ins and outs of HS2, but 30 day payment terms are legally required for all public contracts and this fliws down to subbies. I wonder what the details were.
Public authorities myst publish payments compliance notices every 6 months to show how long it has taken them to mske payments to suppliers above £30k.
As for entanglements between main contractors and subs, aren’t there collateral warranties?
Not my area of expertise, but very interesting.