Sally Hawkins' double trouble with Woody Allen

Sally Hawkins has joked she's not sure whether Woody Allen realises he cast her in two films.

The British actress has worked with the famed director twice, appearing in Cassandra's Dream and Blue Jasmine.

In the 2007 crime drama Cassandra's Dream she played the blonde Kate, while in 2013's Blue Jasmine her character Ginger sported brunette hair.

It's an honour for Woody to work with someone twice and Sally admits she's not sure how it happened.

"Half of me wonders if he realises that was me in both! Different hair colours, different accents..." she laughed to Time Out London.

"He's one of the coolest people, Woody Allen. We were talking about people on the spectrum, and he has Asperger's. It hasn't stopped him. He's not one for chit-chatting. He's very efficient and he knows what he wants. I love that.

"Some directors love to talk and analyse. But he just wants you to be the character and not worry about the process. He'll tell you if he doesn't like it. He often does!"

Sally's big break came in Mike Leigh's All or Nothing in 2002 and they worked together again on Happy-Go-Lucky and Vera Drake. She would still drop anything for the filmmaker and says he changed her life.

Next up for the 38-year-old is X+Y, in which she plays the mother of a child with autism. She read a lot of books to understand her character.

"She's a complicated character. All she wants is for her son to connect with her emotionally," Sally explained.

"She understands intellectually why he's not able to. But emotionally it's incredibly difficult for her."