Hugh Grant has admitted he spent a year being terrified of working with Meryl Streep before they made their new film together.
Hugh plays Meryl's common-law husband and manager St Clair Bayfield in Florence Foster Jenkins, about the tone-deaf operatic soprano of the same name.
The pair posed for photographs together at the world premiere of the movie at the Odeon in Leicester Square but Hugh said he did not always feel so comfortable with the Oscar-winning actress.
He said: "I was terrified of her really and I signed up a year before we shot so I had a whole year of being frightened.
"I would wake up in the middle of the night screaming sometimes, thinking 'I have to do hard emotional scenes against Meryl Streep'. You have to raise your game."
He added: "She's such an icon, it's very odd to be in her orbit at all."
Jenkins was a New York heiress who sold out Carnegie Hall despite mockery and criticism, and Hugh said he hopes she will appeal to British audiences who root for the underdog.
He said: "Someone pointed out to me the other day that in things like Britain's Got Talent they love the people that are really bad almost better than the people who are really good, so hopefully there is an audience for this film here."
One thing the Notting Hill star is sure of is Jenkins would have wiped the floor on talent shows.
"I can't see how she wouldn't have won, she really was a sensation in her day," he said. "It's quite something to fill Carnegie Hall when you can't sing a note."
The film is directed by Stephen Frears, who is also responsible for The Queen, starring Dame Helen Mirren, and Philomena, starring Judi Dench.
However, he said he does not deliberately choose projects starring strong women of a certain age.
He said: "It's unconscious. I dread to think what that says about me, I had a very strong mother."
The director added that he only had to tell Meryl to sing worse on one occasion, despite the fact she has a good singing voice in real life.
Florence Foster Jenkins is released in UK cinemas on May 6.