Years ago at an FSTA meeting at Shabby Wood, when the subject of contractor financial stability was raised, the civil serpents dismissed it with the comment "No government PFI contractor will ever be allowed to go bust...."
On the other hand Beags, some of us could see the problems a mile away. I was 'told' to PFI a Mission Trainer. There was a form to fill, as there always is. I wrote 'NO' in the 'overseas sales?' box, disaster was avoided, and programme delivered ahead of time, to cost and better performance. The same day, Apache rolled over on their equivalent and (presumably) said Yes to overseas sales. Not sure how many they sold. Then Tony Blair was voted in, inherited the mess, but let it ride.
Financial stability of contractors used to be a big deal. But at around the same time, a major contractor approached MoD to warn it was not going to make a profit on a major project. The project team was gathered and told to get off the company's back, they could deliver late and if it didn't work, that's ok. Senior staff approved the waiving of key elements. But there's certain things you can't just waive, as the aircraft can't fly. Westland did the work and billed the prime at the end of the job. They made an even bigger loss after that.