Famous names ranging from Annie Lennox and Dame Judi Dench to the Archbishop of Canterbury have implored the Government not to sell off the country's publicly-owned forests.
Almost 90 prominent figures signed a letter claiming that such a sale would be "misjudged and short-sighted".
The long list of concerned celebrities, politicians, media figures and others includes artist Tracey Emin, model Lily Cole, chef Hugh Fearnley-Whittingstall, former Mayor of London Ken Livingstone, novelist Julian Barnes, actress Gillian Anderson, broadcaster Dame Joan Bakewell, actor Richard E Grant and designer Dame Vivienne Westwood.
The letter by the Save England's Forests campaign said a bill being debated in Parliament would allow the Government to sell the entire public forest estate to commercial interests on the open market.
It also expressed fears that over time, access to currently public woodland would become limited and its protection eroded.
The campaigners wrote: "We are an island nation yet more people escape to the forest than to the seaside.
"Our forests nurture countless species of native plants and wildlife. We have relied on them since time immemorial yet we are only a heartbeat in their history...
"We, the undersigned, believe it unconscionable that future generations will no longer enjoy the guarantee of a public forest estate."
They urged the Government to suspend any significant sales "until the public has been fully consulted".
They added: "We expect our leaders to engage in real dialogue with communities throughout the country to create a sustainable future for our public woods and forests."
The campaign was launched in response to the Government's announcement last year that it was consulting on "new ownership options" for the public forest estate.
Environment Secretary Caroline Spelman has insisted there are no plans to sell nature reserves and promised that community groups and charities would play a greater role in protecting important habitats.
The state currently owns 18% of forests and woodland in England but spending cuts could result in them being sold off or given away.
Ms Spelman reassured critics of the plans that not a single tree could be felled without a licence from the Department for Environment, Food and Rural Affairs (Defra).
The department has also assured the public that access rights will not be lost.
In a message on its website, it said: "The interest this has generated clearly shows that the public care about the country's forests.
"We do too and that is why protection will be in place for the many plants and species that call them home and for the public to continue to enjoy.
"We urge anyone with an interest in this issue to wait for the consultation to be published and see our plans in full."