Bill Moyes, the executive chair of the foundation trust regulator Monitor, has ended speculation that his role might be extended until the election.

Giving his valedictory speech to the NHS at the Healthcare Financial Management Association conference in London last week, Bill Moyes promised “this will be my last appearance in front of a health audience”.

People need to be thinking about a range of scenarios and a range of downsides, rather than just what they have been told

He was speaking the day after the chancellor published his pre-Budget report, which set out a real terms freeze in NHS finances. Mr Moyes warned the figures were likely to worsen.

“If I were a board member, I wouldn’t be saying we now know what’s required and we understand the detail,” he said.

“People need to be thinking about a range of scenarios and a range of downsides, rather than just what they have been told.”

He said one thing that was now “fixed” was that when government talked about “efficiency savings” it increasingly meant “cash”, not extra productivity.

“It’s about doing more activity for a lot less money,” he said.

But he said he was “concerned” that when Monitor asked foundations to revise their economic downside plans earlier this year more than half came back with downside scenarios which were even more optimistic than their original plans. He said around a quarter of the plans were so poor they were “absolutely worthless”.

However, he argued the best way for a hospital to survive the recession was to become a foundation trust, which he said went hand in hand with better governance and financial viability.

Mr Moyes said it was “disappointing” that six years in, only half of the relevant organisations had been deemed good enough to become foundations. He said he was particularly disappointed that a number of big teaching hospitals - such as Leeds, Nottingham and Leicester - had not made it.

He said: “If you can’t demonstrate you are financially viable, who’s going to believe you when you make other claims? I think they will regret it.”

Irrational optimism is the best prescription for NHS managers