He is best known for his leading roles in US dramas Homeland and Billions.
And while Damian Lewis, 46, has perfected his American accent, he revealed his wife Helen McCrory, 48, lives in fear that their two children – Manon, 10, and Gulliver, nine – will pick it up from him.
The star keeps up his adopted accent away from film sets, but he draws the line when it comes to inside the family home.
He told Mr Porter: ‘I don’t do it in front of them. They once spent a school term in the US and they started copying the accent in this comical, exaggerated way, elongating their vowels. I put a stop to that. My wife has a horror that the children will start talking American if we spend too much time out there.’
Damian’s friends back in Blighty have also given him stick for altering his voice, but he doesn’t let their criticism affect him.