The Great Gatsby star appears in a new movie adaptation of Thomas Hardy's classic book, which is set on a sheep farm, and she has now revealed producers initially refused to let the cast shoot any scenes with the film's woolly extras.

Mulligan reveals she was forced to act with a sheepskin rug in place of a real animal, but the plan just did not work.

She tells U.K. talk show host Graham Norton, "It was a health and safety thing, you can't touch anything because of the insurance and they didn't want us to act with real sheep. They were adamant we shouldn't go near the sheep so they made us have a sheep double - a sheepskin rug taped to a big water bottle, which they bounced around in the water... We gave that a go for a minute but we couldn't and said, 'Give us the sheep.'"

The interview airs in the U.K. on Friday night (17Apr15).