but can any of the financial bods out there tell me how bad this actually is ?
Think you could start becoming the equivalent of a subprime mortgage with assistance of a lender of last resort.
You will get leases but you will have to pay up front and at a premium.
Additionally you may find that airports require you to pay fees up front for landing fees and fuel and potentially seize aircraft where these are unpaid.
Bottom line is you need a good line of credit who will support you while you get a decent business plan or investor on board.
Hopefully they will survive but it will be tight for a couple of months.