Some museums and galleries may never reopen despite getting the green light to do so by the Prime Minister, according to the Art Fund.

Boris Johnson told the House of Commons that museums and galleries in England can welcome visitors again from July 4.

But there will be no rush of reopenings on that date – while some closed down in just 24 hours, it will take far longer to reopen.

Others said that their futures depend on international visitors being able to visit once more.

And Britain’s heavyweights, including the Tate and British Museum, are not expected to open on July 4.

When museums and galleries do open, they could also look very different – possibly without the cafes and play areas that bring in so many.

Art Fund director Jenny Waldman said while it was doing “everything we can to support” museums and galleries, many would need Government support to “help secure their future”.

“It’s great news that museums will be able to start opening their doors again from July 4 but for many this will take longer and the future of these vital beloved spaces remains uncertain,” she said.

She warned that some will never recover from lockdown.

“The lockdown closures have hit museums’ finances incredibly hard – some may never reopen and for those who can, social distancing measures will drastically limit visitor numbers and associated income that make them economically viable,” she added.

The heads of Tate, the National Gallery, British Museum, Victoria And Albert Museum, Science Museum Group and Natural History Museum are all yet to confirm opening dates.

“We will now work closely with Government, trade unions and supporters to see how and when we can open our doors again in a financially sustainable manner, for the long term,” they said.

“The British public have faced a wretched few months of isolation, loss and anxiety in confronting the Covid-19 pandemic.

“The reopening of museums – whose galleries speak to the creative, resilient power of the human spirit – will provide solace and inspiration as Britain looks to the future.”

Their collections are there “to be discussed, challenged, and loved – a role of particular significance as we reflect on current debates around crucial issues including racial equality, social justice, and climate change”, they said.

The Florence Nightingale Museum has previously warned that it might not survive.

Its director David Green said it was “very pleased” that it could now plan to reopen on August 1.

But he said that “perhaps the most crucial threat to the future of the museum now is how long it will take for international visitors to begin to return to London”.

“The sooner they begin to return to the UK, the better it will be for the museum and for everyone in the cultural world,” he added.

He ruled out reopening on July 4, to make the museum safe for visitors and staff.

“On March 17, we were able to close and shut down our operations in 24 hours, opening up again will require more work as we restructure the museum and begin a whole new way of working,” he said.

Fewer visitors because of social distancing measures and changing the museum to cope with the measures “will place an extra strain on finances that have already been stretched thinly by the total lack of income since lockdown began”, he added.

The Charles Dickens Museum urged British visitors to visit to make-up for the shortfall in international visitors, although it too will not open on July 4.

Its director Cindy Sughrue said: “Around half of our visitors come from abroad but we are hoping that Londoners and people from across the UK will choose this moment to come here.

“We are road-testing different systems and routes within the museum, considering possible changes to opening hours and planning a timed entry booking system – in short, the whole museum set-up is adapting to the new conditions.”

Sharon Heal, director of the Museums Association, said visitors should expect a different experience.

She also warned that many face an uncertain future because of lost income in lockdown, lower visitor numbers once they reopen, the cost of bringing in safety measures and expected cuts to local authority budgets.

“Where they can, museums are planning measures such as one-way systems and timed entry and implementing strict health and safety measures in line with Government guidance,” she said.

“For those museums that do reopen next month the experience for visitors will be different – cafes, interactives and play areas might not be open, but the welcome from front of house staff will be as warm as ever.

“Museums are eager to reopen but substantial financial investment will be needed from Government to ensure the future sustainability of our much-loved museums.”