Martine said that she and Hugh “bring out the best in each other”.
Martine McCutcheon has admitted that she got her first lines wrong when she reprised her role in the Love Actually sequel.
The 2003 movie is being revisited in a 10-minute sequel for Comic Relief.
Martine told Heat magazine: “My very first line, I got completely wrong. It ended up sounding Chinese!
“Hugh was like, ‘Ah, right, McCutcheon’s back.’”
Martine’s character and Hugh’s Prime Minister alter-ego fell in love in the original movie.
“Me and Hugh are like chalk and cheese – that’s what makes us work,” Martine said of the pair.
“He’s nervous about dance scenes whereas I go, ‘Yeah!’ and get stuck in. We bring out the best in each other.”
She added of her co-star: “Hugh championed me from the beginning. Without Hugh, it would be like salt without pepper.”