Nearly 30 trusts are unlikely to hit the government’s intended date for them to become foundation trusts, the National Audit Office has warned.

The NAO report used documents gathered from trusts by the DH to warn there were “at least 20 trusts that will never achieve FT status in their current form”, and that the most common challenges they faced were financial.

The figure had already been highlighted by health secretary Andrew Lansley on Tuesday and the trusts in question identified.

The report also shows 41 trusts planning to submit their foundation trust applications to the Department of Health by October 2012, with the remaining 52 coming after that.

Twenty-eight of the later applicants plan to submit their application at April 2013 or later, which means they would have missed the earlier DH deadline of April 2014 for all trusts to become foundations.

The April deadline was later relaxed but is still deemed an aspirational target.

None of the trusts in the NAO report are named but one trust plans to get its application in by April 2015.

The report also says aspirant trusts have indicated they will need £375m in loans to help them meet Monitor’s cash reserve, or liquidity, requirements.

Think-tanks and the body representing foundation trusts welcomed the report.

Foundation Trust Network chief executive Sue Slipman said: “At long last the department has a grip on the problem.

“We have been concerned that the drop dead date had gone, but although it is much fuzzier now, there should only be an exception where there is a strong business case that demonstrates that the trusts will achieve FT status in the near future.”

King’s Fund chief executive Chris Ham said: “These issues have been ducked for too long. The recent announcement by the secretary of state backing changes to services at Chase Farm hospital in north London signalled a welcome willingness from ministers to embrace the need for change.

“It is to be hoped that this will be followed by an honest dialogue with the public about the need for some hospital services to close.”

NHS Confederation deputy chief executive David Stout said: “The NAO has hit the nail on the head that the financial and clinical viability of at least 20 trusts struggling to get to foundation status can no longer be ignored.

“There is no easy solution for dealing with these trusts as many of the mainly financial problems they face are long term and deep-seated. What is certain is that, as the NHS faces its greatest ever challenge, propping up services with short term extra payments is unsustainable.”