Emily Blunt had to switch glamorous gowns in an airport bathroom during her 'three premieres in a day' challenge to promote new movie Edge Of Tomorrow.

The Devil Wears Prada actress and her co-star Tom Cruise embarked on the gruelling mission to attend three screenings in three countries within 24 hours to promote the upcoming sci-fi blockbuster on Wednesday (28May14).

While Cruise could simply change suits between stops, Blunt had the tougher challenge of completely overhauling her look for each red carpet appearance.

Blunt arrived at the London premiere in the early morning in a long patterned gown with tousled hair, but by the time she hit the premiere in Paris in the afternoon, she was wearing an edgy, leather number with her hair scraped into a tight bun.

However, she did not have time to get a Hollywood makeover and had to settle for a quick change in a restroom instead. She says, "I went to an airport toilet. It was like a Formula One pit stop. It really wasn't that glamorous."

She later arrived at the New York premiere at nighttime wearing a tight red gown with yet another different hairstyle.

Cruise celebrated completing the challenge on Twitter.com, writing, "We made it! Thanks to all the fans who came to see us - from dawn in London to midnight in Nyc with Paris in between."