Public parks are at a "tipping point" with budgets to maintain them cut by up to 97%, a report by MPs has warned.
The squeeze means parks face a return to the neglect of the 1980s and 1990s unless it is recognised they are "much more than just grass and tulips" and innovative management and funding measures are found.
Housing demand is also putting parks at risk, with new homes "nibbling away" at green spaces in some areas, a report from the parliamentary Communities and Local Government (CLG) Committee says.
But parks play an important role, helping integrate communities, tackle climate change and prevent flooding, reduce air pollution exposure and boost health as well as providing leisure amenities.
Councils should publish strategic plans that recognise parks' wider value and how they could deliver on issues such as promoting healthy lifestyles.
They should also consider the range of alternative models for looking after parks - although they should remain owned by local authorities and be freely available to everyone.
The MPs also entered the debate over the free use of parks by organisations such as parkrun - which hit the headlines when Stoke Gifford Parish Council tried to charge for its weekly runs in a Bristol park last year.
Community organisations, such as parkrun, which do not charge for participation or raise revenue, could be encouraged to contribute volunteer time to help maintain parks or undertake fundraising, the report suggests.
Parks and green spaces are not equally distributed across England, with deprived areas often missing out, and the Government should find ways of improving access, such as using funds targeted at tackling obesity, the MPs urge.
Clive Betts, chairman of the CLG Committee said: "Every local authority should have a strategic plan, recognising that parks are much more than just grass and tulips and bringing in resources from outside the traditional budgets.
"Parks are treasured public assets, as the overwhelming response to our inquiry demonstrates, but they are at a tipping point and, if we are to prevent a period of decline with potentially severe consequences, then action must be taken."
He said the Government had a leadership role to play and volunteers did "fantastic work" but the primary responsibility lay with local authorities.
The vast majority of councils have cut budgets for parks and were likely to cut further, with Newcastle City Council's parks management budget slashed by 97% in five years, the report found.
Impacts on parks ranged from turning off paddling pools and removing green gyms or play equipment to shutting public toilets, reducing opening hours and an increase in litter, vandalism and rats.
While the MPs acknowledged pressure on budgets affected discretionary services such as parks more, they did not believe placing a statutory duty on local authorities to provide and maintain parks would necessarily help.
The Government should issue guidance to councils to work with health and well-being boards to publish joint parks and green space strategies and look at removing barriers to innovative ways of managing public parks.
Green spaces should also be at the heart of planning, with their importance to existing and new communities recognised, the report said.
Ian Stephens, chairman of the Local Government Association's culture, tourism and sport board, said: "Councils understand how important parks are to residents and the value they have in promoting health and fitness, local heritage, public art, festivals and wildlife walks.
"Councils are taking innovative approaches to using park spaces, such as providing pop-up spaces, hosting local events and giving communities a say in how their parks are run."
But central government funding for councils was cut 40% in real terms in the last parliament and funding pressures continued, he said.
Despite the difficulties, he insisted councils were doing everything they could to provide the best possible services.
More than 300,000 people backed a campaign by 38 Degrees on protecting local parks.
Charlotte Woodworth, 38 Degrees campaign director, said: "It is vital the government now takes urgent action to ensure councils around the country have the sufficient resources and funding to protect and maintain our local parks and outdoor space.
"If not, we risk losing them for future generations."
A spokesman for the Department for Communities and Local Government said: "Parks breathe life into our towns and cities and are vital spaces for the whole community to come together to exercise, learn and play.
"That's why last year we announced a £1.5 million fund to deliver 87 pocket parks to benefit those living in urban areas with limited access to green space.
"We're committed to keeping parks at the heart of the community, and we will respond fully to the committee's recommendations in due course."