A survey of leading figures in British cultural life, among them theatre director Sir Nicholas Hytner, ITV chairman Sir Peter Bazalgette, and acclaimed artists such as Nitin Sawhney, Lenny Henry, Beverley Knight and Jo Brand, reveals that most now fear the biggest threat to Britain’s creative reputation is the loss of freedom of movement in Europe after a potential hard Brexit.

For the overwhelming majority of the 50 cultural leaders, the ability of artists to continue to work abroad freely is a higher priority even than maintaining seriously jeopardised levels of funding.

“Brexit has been a total disaster from its inception to its current execution,” said Sawhney, who this year won an Ivor Novello lifetime achievement award for his music. “The impact on the arts will be devastating. It will have a hugely negative impact on the perception of the UK as a multicultural hub of creativity and free expression.”

The results of the research, conducted by the thinktank Global Future and released to the Observer, show a clear level of agreement across dance, theatre, music and the visual arts about the dangers of ending artists’ ability to work freely throughout Europe.

Those creative leaders who took part, including the revered dancers and ballet company directors Tamara Rojo and Akram Khan, along with Alistair Spalding, artistic director of Sadler’s Wells, and Alex Beard, head of the Royal Opera House, spoke with almost one voice, with 46 out of 50 saying a hard Brexit that ended free movement would have a negative or even devastating impact.

For Paul Roseby, director of the National Youth Theatre, where many stars, including Daniel Craig, Matt Lucas, Kate Winslet, Helen Mirren and Idris Elba, began their careers, the health of the creative sector, which the government acknowledges brings in £87bn a year to the economy, is ignored at Britain’s peril.

“It is simply a question of trade really. Although Brexiters are very keen on free trade, they don’t acknowledge this will close down a freedom of trade in a very important area – despite the fact it is a growth market, growing more than any other sector apart from banking.”

For Roseby, like other respondents, preserving freedom of movement comes above efforts to secure investment, because it will immediately damage Britain’s artistic reputation.

The large majority of those surveyed also said diversity was one of the chief reasons behind Britain’s creative success, while 46 respondents felt there was now a big risk to the country’s “soft power and creative reputation”, and 41 believed that morale had fallen since the EU referendum.

Roseby also pointed to the recent decision of the European Youth Orchestra to relocate to mainland Europe, cutting off many young musicians in the UK from playing and learning with international artists. “The impact is going to be on diversity of talent,” he said. “We rely on that cultural diversity, and when that goes we will be isolated. It is about perceptions across Europe, and sadly the perception is already changing out there. It is a very serious question across the arts community.”

Khan famously performed to great acclaim at the Olympic opening ceremony in 2012, but it is now the fear of Farooq Chaudhry, producer of Khan’s dance company, that the threatened changes will signal the end of a great creative era.

“In the past 20 years Britain has been living in a golden age of arts and culture,” he said. “We have fostered a whole generation of artists who have led the way in the global artistic community with their brilliance and values of innovation and excellence. This has been built on a platform of international collaborations and cooperation. It would be catastrophic if this exchange was shut down. Not just for us, but for the whole world.”

Working in the non-verbal world of dance, Chaudhry said that the nationality of artists has always been less relevant than their talent. “Freedom of movement for that talent is vital if we are to refresh our ideas and stimulate creativity. The key in art is to find new ways to do things, that is how we make interesting work, and we cannot do that without open doors. Otherwise you just continue to do things in the same way and become irrelevant.

“We will soon be culturally devalued. If it doesn’t kill our creative sector, it will certainly seriously diminish it.”

His pessimistic predictions are backed by Sawnhey, who said: “The lack of any clear path to how artists will perform and collaborate with European partners is also exacerbated by inadequate current provision for new funding mechanisms to compensate the huge losses that will result from touring and travel restrictions.”