NHS Trust Development Authority chief executive David Flory has warned “a significant proportion” of the trust sector has no “clear plan for sustainability”.

Mr Flory’s report last week to the board of the organisation responsible for 99 non-foundation trusts said this was “cause for concern” and that by 20 June the trusts would have to submit five-year plans setting out “a clearer direction”.

It is expected the planning process will see some trusts concede they cannot continue as solvent, standalone organisations and the TDA will then consider what form they should take in the future.

The 99 hospital, community, mental health and specialist trusts have had to report to the TDA since it was created as an arms-length body of the Department of Health in June 2012.

Getting trusts to foundation status has been a long-standing problem for the health service, and it was only in March 2013 the TDA dropped its previous line that all but “a handful” of trusts would have been authorised by the end of this month.

Only two trusts have been authorised over the past year after concerns that the cost cutting undertaken to meet Monitor’s financial requirements had in the past led to unsafe care at Mid Staffordshire and University Hospitals of Morecambe Bay.

Mr Flory’s comments came as the outgoing chief executive of NHS England, Sir David Nicholson, told HSJ that a policy of getting all trusts to foundation status could not be implemented and that people were “using lots and lots of energy flogging a [foundation trust] model which is not going to work in the future”.

Asked to comment on Sir David’s remarks, a spokesman for the TDA said: “The priority for all NHS trusts is to deliver high quality, sustainable services. This means ensuring the best possible healthcare is provided for local people, now and long into the future.”

The Department of Health has no plans to change policy on foundation trust authorisation but said in a statement it had commissioned Salford Royal FT chief executive Sir David Dalton to review “the feasibility of alternative models such as chains or group structures.”