Artists Damien Hirst, David Hockney and Tracey Emin have joined more than 100 British artists who have signed a letter condemning the British Council.
Emin represented Britain at the Venice Biennale art show last year
They are angry over claims made in the Guardian newspaper that the council is planning a radical shake-up.
The letter says the artists are "specially concerned" at the demise of the council's visual arts department.
The British Council said: "People are commenting on something when they haven't seen the final picture."
The spokeswoman added: "We'll retain specialist expertise across sectors and we're undergoing extensive consultation over the next couple of months with key people from the sector.
"Essentially all we have at the moment is some internal restructuring," she added.
The letter also said: "Why, without any consultation, does the British Council seem intent on abandoning the best proven means of conducting cultural relations through the arts?
"The department's programme of over 60 shows a year... would be an inexplicable and, indeed, tragic loss. These exhibitions... represent Britain in the best possible light."
According to its website the British Council Arts group "brings the best of UK arts to the rest of the world".
It exists "to build mutually beneficial cultural and educational relationships between the United Kingdom and other countries, and increase appreciation of the United Kingdom's creative ideas and achievements".
Venu Dhupa, director of arts for the British Council, told the Guardian the issue was whether the council should have a basket of competing art forms, or bring them together to be a "united force for change".
She said: "What I'm trying to do...is making sure that the arts are a strategic transformation force, because that's when they are at their most powerful."
Other signatories include Tate director Sir Nicholas Serota, Gilbert & George, Joanna Lumley, Melvyn Bragg and Antony Gormley.
Speaking to the newspaper artist Rachel Whiteread said: "It's appalling really, considering the amount the British Council has done over the years for highlighting British contemporary art all over the world and helping it have an enormous reputation."