The Heat director Paul Feig reveals that casting Sandra Bullock and Melissa McCarthy in his hit comedy was ''all or nothing."

The 62-year-old Bridesmaids helmer insists he didn't want any other actresses to star in the new movie.

Speaking to, Feig said: "For me it was always them or nothing. When the script came to me I was told that Sandra was interested, so I was like, 'Awesome', because I wanted to work with her. And then Melissa and I had been trying to figure out something to do for a long time and the minute I read it, I was like, 'This is so great for her.'

"There was a moment where scheduling looked like it might not work out for either one of them and so the studio was like, 'Well, who else?' Honestly, there's plenty of women I love who I want to work with, but I was like, 'I don't know.' These two, for some reason... this combo feels like gold to me, and so we pushed it through."

The Heat hits cinemas on July 31.