The National Trust have told 1,200 of its staff they face redundancy as it plans to make £100m of annual savings following the impact of Covid-19.
The body, which looks after a large amount of farmland across the UK, expects to lose up to £200m this year as a result of the pandemic.
When the UK went into lockdown the trust closed all its houses, gardens, car parks, shops, cafes, holidays and stopped events, losing 'tens of millions of pounds of support'.
Director-General Hilary McGrady said the announcement was made with 'huge regret'.
"Our charity has survived so long – through two world wars and a number of economic downturns, thanks to staff, volunteers and supporters.
"We would not be making these savings had we not exhausted every other possibility. We need to act now to ensure we are sustainable in the future."
The National Trust has around 5.6 milion members and more than 500 heritage and conservation sites across the UK.
It cares for over 250,000 hectares of land in partnership with 1,500 tenant farmers.
The trust said it had saved millions through the furlough scheme, borrowing, and deferring projects, but that it still needs to reduce costs to protect its future.
Ms McGrady said the short-term hit, coupled with the longer-term implications of social distancing and suppressed trading, meant there was a need for a full review into spending and priorities.
She said: "All aspects of our home, work and school lives, our finances and communities have been affected, and like so many other organisations the National Trust has been hit very hard.
"The places and things the National Trust cares for are needed now more than ever, as the public needs to recuperate and recover their spirit and wellbeing. Our focus will remain on the benefit we deliver to people, every day.
"We have reviewed our spending and ways of working to ensure we emerge from this crisis in a strong position to keep on protecting and caring for places so people and nature can thrive."