Which hit song by the singer Duffy featured in the 2008 film "Sex and the City: The Movie"?

Explanation

Aimée Anne Duffy (b. 1984) is a Welsh singer and songwriter. She mostly sings soul music. In 2007, she signed a record deal and had her popular breakthrough with her debut album. Duffy was no. 1 on the UK Singles Chart with her hit song "Mercy", as the first Welsh woman in 25 years. Mercy also appeared in the film "Sex and the City: The Movie", which led to her success in the US. She has released the albums Rockferry (2008) and Endlessly (2010).