Accident and emergency or maternity services at Kingston Hospital could be axed – putting pressure on St George’s – as part of a radical shake-up to health services.

NHS London said the plans were only at a draft stage but MPs and patient groups have reacted angrily, claiming the public were not being fairly consulted and decisions were being made “behind their backs”.

A loss of a major department at either hospital would mean longer journey times for expectant mothers and other ambulance emergencies, opponents said, and would increase pressure on neighbouring services.

Campaigners also questioned if cuts were being forced because of a lack of money, and while NHS London insisted the plans were part of a planned reconfiguration of services, it did not deny the changes would save money.

Putney MP Justine Greening said: “People do not have a clue about what is going on. If Kingston goes is St George’s going to cope? I’m very worried about it, especially the way the process has been carried out.”

Ms Greening, who spoke at a House of Commons debate on the issue on Tuesday, said: “On one hand we are told it is about putting services closer to people, but on the other hand there’s a large NHS shortfall.

“People are deeply concerned as it seems to be happening behind their backs.”

Roger Appleton, chairman of patient health group Wandsworth Link, said: “Journey times to A&E is a concern, and if the argument is about cost effectiveness we need to see calculations that the savings are worth it.”

Healthcare for South West London has been looking at services at St George’s in Tooting, Mayday in Croydon, St Helier in Carshalton and Kingston Hospital, since June last year.

The review, which was worked on by 100 clinicians, concluded only three of four hospitals in south-west London should have a maternity unit or an A&E.

While it is thought unlikely St George’s would lose its A&E, as it is the major trauma centre for the area, Kingston Hospital is viewed as vulnerable. Despite it expanding maternity services in the past three years, a leaked document showed 16 out of 18 preferred options involved the loss of a major service at Kingston.

The review’s findings were due to be published in December but have been delayed twice and are not now expected until after the general election, prompting MPs to ask health bosses to make the plans public.

A spokesman for NHS London said the story was “scaremongering” and there would be “no changes to services without consultation”.

But, he said: “Doing nothing is not an option for the NHS. As the capital’s population continues to grow, more people rightly expect high quality care all the time. Put simply, we are building a health service around people rather than buildings to give people a better standard of care.

“Our challenge is to use our budget to treat more patients... some will say we should continue as we are but this is unaffordable and will leave some Londoners without access to the care they deserve.”