The National Lottery has set up a £50 million emergency fund for British heritage sites after almost 50% said they will not survive beyond six months if the coronavirus shutdown continues.

Grants of between £3,000 and £50,000 will be available to sites already funded by the organisation, primarily to train the workforce in digital skills to help them through the Covid-19 crisis.

These include digital fundraising, social media and online communications, and how to run online events and activities.

A survey by the National Lottery Heritage Fund of more than 1,250 organisations in late March found 82% reported the shutdown was a high or moderate risk to their long-term viability.

About 35% said their financial reserves would be depleted within four months, and 46% said they would not be able to survive more than six months.

Asked what support they needed from the Heritage Fund and its partners, 75% said greater flexibility for existing projects and grants, and 53% said emergency funding.

The £50 million emergency fund will use cash diverted from planned new grants, with all new awards halted with immediate effect, the National Lottery Heritage Fund said.

It said priority will be given to sites where there is limited or no access to other sources of support, or where heritage is most at risk.

The organisation said it will continue to support 2,500 projects already in delivery – a commitment of £1.1 billion.

Eilish McGuinness, executive director of business delivery at the National Lottery Heritage Fund, said: “We know that circumstances are incredibly challenging for our heritage community right now and we want to do everything we can to support them.

“We hope this new emergency fund and our investment in digital capability will be a lifeline for organisations affected.

“Heritage has an essential role to play in making communities better places to live, creating economic prosperity and supporting health and wellbeing.

“All of these are going to be vitally important as we emerge from this current crisis.”

Heritage minister Nigel Huddleston said: “It is important that we do all we can to ensure our nation’s remarkable heritage landscapes, buildings and monuments – and the hardworking organisations that protect them – are supported at this difficult time.

“Heritage plays an important role in our communities by supporting jobs and economic growth as well as helping us to understand our shared past.”

Duncan Wilson, chief executive of Historic England, welcomed the fund, adding: “We are also planning emergency financial support to run alongside this and other measures introduced by the Government and our partners in the heritage and cultural sectors, and will announce details soon.”

Gerald Vernon-Jackson, chairman of the Local Government Association’s culture, tourism and sport board, also welcomed the announcement.

“Preserving heritage sites – war memorials, ancient castles and houses – contributes to local priorities by boosting economies, attracting visitors, developing workforce skills and creating great places to live,” he said.

“So it is important that this funding is available to ensure that our heritage sites are ready to open for business as usual when the coronavirus pandemic is over.”