SINGAPORE: Two senior members of Singapore's largest opposition party have resigned after admitting they were in a relationship, Workers' Party chief Pritam Singh said on Wednesday.

Member of parliament Leon Perera and the party's youth wing president Nicole Seah handed in their letters of resignation after a video was posted on social media earlier this week showing the pair holding hands, Singh told a press conference.

"The Constitution of the Workers Party requires candidates to be honest and frank in their dealings with the party and the people of Singapore," Singh said, adding that the pair's behaviour was "unacceptable.

This is the third scandal to hit the city-state in a week, shocking Singaporeans who are used to stable and drama-free politics.

Last week, the transport minister was arrested in connection with a graft investigation, and on Monday two lawmakers, including the house speaker, quit because of an inappropriate relationship.

(Reporting by Chen Lin, Writing by Xinghui Kok, Editing by Kanupriya Kapoor)