Recovering from the pandemic is expected to take the National Trust more than four years - after it suffered a huge drop in visitor numbers, with a fall of almost 50pc at one Norfolk site.

The Trust, which owns some of Norfolk's most popular attractions including Blickling, Felbrigg and Oxburgh Halls, saw figures plummet in 2020 as a result of lockdowns and social distancing measures.

This has left it with far less cash to spend on conservation projects and a spokesman said it will be "at least four years before our financial position returns to pre-pandemic levels".

It comes at a challenging time for the Trust, which has been under fire from critics - including some disgruntled members - who have accused it having a "woke" agenda, with an overemphasis on links between its properties and slavery, among other issues, at the expense of its core function of preserving properties.

From March 2020 to February this year, Blickling had 115,535 visitors, down from 205,704 the year before, a 43pc fall. Felbrigg had 78,187 visitors in the 12 months to March this year, down from 129,627 in 2019/2020.

The trust spent £168.8m on conservation projects in the 12 months up to March 2020, and that figure was halved to £83.8m during the 2020/21, when much of its income dried up after it was forced to close houses, shops and cafés.

Hilary McGrady, its director general, said the pandemic was not the first crisis the charity had faced and it would not be the last.

"The pandemic has given us all cause to reflect," she said. "At 126 years old, thanks to our members support, we've endured World Wars, economic crises and now a pandemic, and we're still here. Together we are still working for nature, beauty and history - for everyone, for ever."

During the pandemic, the Trust suspended recruitment of members, resulting in a 1% drop. However, there are signs a recovery is under way. New subscriptions broke records over the summer, with 159,732 new sign-ups in August, the third highest-ever month. Last month, a member joined every 23 seconds.

The dispute between traditionalists and modernisers over the Trust's so-called 'woke agenda' came to a head at the organisation's AGM at the end of October when a rebel group of disgruntled members narrowly lost two of their three resolutions.

The group, called Restore Trust, claims to have a £50,000 war chest and about 10,000 present and former Trust members in its ranks. It has accused the organisation's leadership of neglecting its conservation role at the expense of political and social causes.

Last year, the Trust released a report into 93 of its properties - including Blickling, Felbrigg and Oxburgh - highlighting their connections with slavery and colonialism.

Other regional attractions run by the Trust include Sheringham Park, Brancaster Estate, Blakeney National Nature Reserve, Horsey Windpump and Darrow Wood, near Harleston.