More than 400 of the UK’s leading artists, musicians and creative figures including Nick Cave, PJ Harvey, Meera Syal, Simon Callow and Johnny Marr have signed a letter calling on the government to release funds to support the creative industries, warning that unless more is done the country could become “a cultural wasteland” because of the economic damage done during the Covid-19 outbreak.

The letter, which is written by Creative Industries Federation (CIF) and addressed to the chancellor and culture secretary, appeals for urgent funding for creative organisations and professionals who, it says, are “falling through the gaps of existing government support measures”.

Signatories of the letter also include Anish Kapoor, Jeremy Deller and Jonathan Pryce, who argue the government “cannot allow the UK to lose half of its creative businesses and become a cultural wasteland”.

The singer Rufus Wainwright, who also signed, told the Guardian artists “protect the minds and souls of a nation”, and it could be “criminal” for the UK to not support them during the crisis.

He said: “Artists are creating so much content online that people can experience in their homes. They have not stopped producing and it would be a crime as a society to not support them through this crisis as they are nourishing us.”

Wainwright added that Germany, which announced a federal aid package worth €50bn (£43 bn) for freelancers and small businesses with Berlin distributing €5,000 payments to individual freelancers (including artists), was a country that has effectively supported the arts and the creative industries.

In March, the UK chancellor, Rishi Sunak, unveiled plans to pay self-employed workers up to 80% of their recent earnings, but was criticised when industry groups claimed many were ineligible for any financial support under the scheme.

Arts Council England also announced a £160m emergency response package that gives artists access to cash grants of up to £2,500, with £50m available for organisations outside its national portfolio, and another £90m going to national portfolio organisations.

Caroline Norbury, CEO of CIF, said the creative sector was in “deep trouble” despite the government funding meant to support workers who have been affected by Covid-19 lockdown measures.

She said: “While government support measures for businesses and the self-employed are welcome, we know that there are still thousands of creative organisations and freelancers who are falling through the gaps, and who simply will not get through this crisis without urgent cash support.”

The letter also references CIF research that shows that one in seven creative organisations have reserves to last until the end of April, with half having money that will last beyond June.

The letter is the latest appeal for support from the government by leading British cultural figures. Last week, the artistic director of the National Theatre, Rufus Norris, told the Guardian that some theatres had only days before they could go out of business and urged the government to offer more support to freelancers.

“If the furlough scheme doesn’t continue, yet we stay closed as an industry, then it’s very hard to imagine how the sector will survive,” he said. “I would like the government to increase and broaden the support of freelance artists who are suffering very badly.”

Norris’s comments followed those of the playwright James Graham who said an “aggressive government bailout” was the way to ensure the sector survived Covid-19 and that “working-class actors and artists might be the ones who struggle to find themselves back on those platforms and in those spaces”.

The international curator Hans-Ulrich Obrist told the Guardian a multimillion pound public arts programme, similar in scale to Franklin D Roosevelt’s Public Works of Art Project (PWAP) and Works Progress Administration (WPA), which was rolled out during the Great Depression in the 1930s, was needed to support artists during and after the Covid-19 outbreak.