The NHS is under pressure from councils to explain why they are being kept in the dark about a major transformation of how health services are delivered across mid and south Essex.

Councillors in both Southend and Thurrock have slammed NHS England for being tight-lipped about a demand for five clinical commissioning groups (CCGs) to put together a plan to merge in just two months.

Despite the CCGs working in close partnership with local authorities on schemes ranging from mental health strategies and child social care to tackling public health issues and special educational needs, councils have not been told about the merger.

Without council input, the delivery of a wide range of services could be impacted and councils could be left uncertain over healthcare funding.

Southend Councillor Matt Dent speculated that the NHS could be avoiding the councils after Southend and Thurrock called for another health transformation scheme, known as the STP, to be scrutinised by the secretary of state.

He said: “It is a possibility that the NHS are not coming to Southend and Thurrock because the are worried we might object in the way we have to the STP. I would hope they are not trying to sidestep the scrutiny process and democratic institutions, but it is a worry that we haven’t heard anything.

“With all the cloak and dagger around this, how far does the lack of knowledge extend? How much were CCGs aware of what is going on, it’s hard to judge how far this fog of information extends. It is certainly worrying that someone at some level is keen on not giving councils information to scrutinise this.”

Councillor Leslie Salter, chair of the People Scrutiny Committee, said on Thursday that she had not been briefed on the NHS plan but she expects it to be discussed at a future scrutiny committee but no meetings have been scheduled before September 30 – the deadline for the plan.

NHS England and Southend’s CCG have both refused to provide any information on why there has not been any communication with the councils or the impact of the merger.

Thurrock’s CCG did notify Thurrock Council but no official correspondence has come from the NHS.

Councillor Victoria Holloway, chair of Thurrock’s health overview and scrutiny committee, said: “In the NHS’ long term plan it was set out that this was going to happen so we knew something may be on the cards but they haven’t even consulted the directors of the council themselves.

“These are directors have safeguarding and commissioning responsibilities and not consulting them is extremely bad and shows they are failing on multiple levels.

“We expect to be aware a plan is happening, so while it was on the radar we were not aware of the decision to forge ahead to quickly and without consultation – to draw up a plan for the whole of mid and south Essex without consulting anybody but clinicians is ridiculous.”

Thurrock Council is expected to discuss the issue further at a full council meeting on Wednesday.

An Essex County Council spokesperson said: “We are aware the CCGs are in discussions about how they may work closer together, including moving towards shared management.

“However to date we have not received a formal notification to fully merge the CCGs.