United Kingdom, Dec. 5 -- Kate Winslet has revealed Dame Helen Mirren broke her own "personal rules" to star in her new Christmas film Goodbye June.

Winslet, 50, made her directorial debut on the drama movie, which was written by her 21-year-old son Joe Anders, which follows four siblings who gather around their dying mother and she takes a turn for the worse over the holiday season.

Mirren, 80, plays the titular mother June and despite initially telling Winslet she never portrays cancer patients of dementia sufferers on screen she broke her own rules after reading the script.

Appearing on The Graham Norton Show, Winslet said: "When I was telling her [Mirren] about the film she said, 'I am going to stop you because I have two personal ...