British film, TV and theater stars including Helen Mirren, Jeremy Irons and Julie Walters have warned that government arts cuts could damage the U.K. industry.

In a letter published in the Observer newspaper on Sunday, the celebs cited the withdrawal of local authority support, financial pressures faced by the Arts Councils and the BBC and the abolition of the U.K. Film Council, which backed “The King’s Speech,” as factors that create “the biggest threat to funding that the arts and culture have experienced in decades.”

The group, which also includes helmer Mike Leigh, Kenneth Branagh, Imelda Staunton and David Tennant, said that “the return from cultural investment is staggering” and pointed out that the arts and film biz contribute more than £7 billion ($11.3 billion) to the economy annually.

In October, the government announced that the Arts Council England, which distributes money to galleries, theater groups and various arts venues, would see a 30% cut in its budget. According to Culture Secretary Jeremy Hunt, the national net cut in arts funding is only 11%.