The planes that have landed in the UK are being impounded by their airports. If an airport is not paid the unpaid fees within 56 days, they are entitled to auct

The planes that have landed in the UK are being impounded by their airports. If an airport is not paid the unpaid fees within 56 days, they are entitled to auction the impounded plane to recover lost costs. I would suspect airports are very unwilling to let those aircraft go anywhere until all the bills are paid as they might be only guaranteed way of getting money at this point.