NHS England has formally intervened in one of the three success regime areas, ordering its clinical commissioning groups to pool functions and create a single plan.

Legal directions – the national organisation’s most severe form of intervention – have been imposed on Castle Point and Rochford, Southend and Thurrock CCGs.

They are ordered to “develop a joint committee”, which will also cover the other two CCGs in the mid and south Essex success regime area and sustainability and transformation plan footprint. These are Mid Essex, and Basildon and Brentwood.

Together they must “produce a joint commissioning plan… approved in advance” by NHS England, which will set out what functions and funding will be delegated to it, as well specifying a chair and lead officer for the joint committee.

Mid and south Essex was one of three health economies that the NHS England chief executive announced in summer 2014 would be a major focus for improvement as part of a “success regime”. The success regime leaders said the legal directions supported the work already under way.

Its three acute providers are collaborating closely, with Clare Panniker now the chief executive of all three. There has been some improvement in their quality ratings and deficits.

The CCGs have been discussing joint commissioning for the past year but have not been able to agree the details.

It is hoped the changes will now lead to streamlined decision making, particularly on the future of acute services, and lower commissioner running costs.

Independent success regime chair Anita Donley said: “The mid and south Essex STP is well advanced and was highly commended in the national assurance process at the end of last year. A joint committee for commissioning is crucial for turning aspirations into reality for local people.”

The success regime and STP programmes are working on a substantial reconfiguration between the three general hospital providers – Basildon and Thurrock University Hospitals, Southend University Hospital, and Mid Essex Hospital Services – which are relatively near each other.

The first draft of the STP, published in October, set out options for an acute reconfiguration which would result in two of the three hospitals losing services and one being upgraded to a “specialist emergency hospital”. The downgraded hospitals would retain emergency departments with 24/7 opening, and still provide some specialist surgery. The plans are expected to be consulted on “later in 2017”.

NHS England said its intervention was “largely due to the need… to form a single decision making group to bring about the effective delivery of the STP”. A spokeswoman said: “The issuing of directions is a necessary intervention to facilitate good local decision making within the health system in mid and south Essex…

“As the mid and south Essex STP continues to engage with local people about the options for change and moves towards full public consultation, it is vital to have a solid decision making function in place. This function will enable them to act cohesively, effectively and in a timely way on the outcome of any public consultation.”

Twenty-eight CCGs – more than one in 10 – had legal directions imposed by NHS England during 2016-17. The three Essex CCGs’ directions were imposed on 31 March and have not been publicised.