It comes as the government looks into its own potential ban, with a consultation closing in the summer.
The families call for those responsible for the issues at the Queen Elizabeth University Hospital in Glasgow to be held to account.
Former minister Justin Madders tells the BBC Labour must stick to its pledge to cap ground rents.
The prince was emotional as he ended his evidence in the trial over alleged unlawful information gathering.
The Office of Road and Rail says it was missing "critical points" when it made a decision.