Labour will halt closures of A and E departments in English hospitals if it gains power on June 8.
Shadow health secretary Jonathan Ashworth said he would launch a full-scale review of such proposals and stop the Sustainability and Transformation Plan (STP) programme if Labour wins the General Election.
Mr Ashworth said: "Labour will put the best interests of patients at the heart of our NHS, so I'm announcing we will halt planned closures to hospitals and other services.
"We will have a moratorium on the STPs.
"We have listened to the hundreds of patients and campaigners up and down the country that have been pleading with the Government to hear their concerns about their local services.
"Threats of hospitals being closed, A and E services moved miles up the road, and children's wards being shut, have caused widespread concern and confusion.
"What is more, these decisions have been decided behind closed doors with no genuine involvement of local people. It's a disgrace.
"The public deserves better. My first job as secretary of state will be to review every single STP proposal looking at what's in the interest of quality of patient care.
"We'll ask a new body - NHS Excellence - to lead that review. And patients and local communities will be involved at every stage.
"Local people should be at the heart of decisions about how care is provided."
Responding to the plans, Health Secretary Jeremy Hunt said: "This is just another nonsensical Jeremy Corbyn idea – last December his shadow health secretary backed these plans and Labour's 2015 manifesto said they would do the same thing.
"These local plans are developed by local doctors and communities, backed by the top doctors and nurses of the NHS, and will improve patient care.
"This is all underpinned by an extra £10 billion for the NHS, which we can only afford thanks to our strong economy."
Liberal Democrat health spokesman Norman Lamb said: "The purpose of the STP process was a good thing – to bring fragmented parts of the system together.
"But it is based on the fantasy that there is enough money to deliver this vision, when STPs will be hundreds of millions of pounds short.
"The real question is: which party is prepared to take the tough action to increase investment? Only the Lib Dems will make the case for increasing tax to guarantee the future of the NHS.
"The Conservatives are reorganising the deckchairs – while the good ship NHS is sinking because they are starving it of funds.
"Hospitals under the Conservatives will close because they are being starved of money, not for clinical reasons. That is a disgrace."