Negotiations are under way for Emily Blunt and Jason Segel to hop on board and keep Jack Black company for Gulliver’s Travels. But the film, directed by Shark Tale and Monsters Vs Aliens helmer Rob Letterman, could threaten Blunt’s secured role as Natasha Romanoff aka the Black Widow in Iron Man 2.

Due to a contractual technicality from when Blunt starred in Devil Wears Prada, Fox hold an option on her which they could use to secure her for the giant adventure, over any other project. But Blunt’s people are squirrelling away, trying to work out the schedule clash so that she can do both. Gulliver begins shooting in the U.K. in late March;  and Iron Man 2, filmed in Manhattan Beach, California starts just weeks later in early April.

Blunt will play a princess that Black’s Lemuel Gulliver becomes infatuated with, and Segel will be Horatio, the friend who rescues him – both of whom will be part the tiny Lilliputian community Gulliver finds when he is shipwrecked on his travels to the Bermuda Triangle.

The film will see Segel – up next in best-man buddy comedy I Love You, Man – reunited with his Forgetting Sarah Marshall director Nicholas Stoller who co-wrote the screenplay.