Sri Lanka, April 29 -- Scotland's first minister, Humza Yousaf, resigned on Monday, triggering a leadership contest as the governing Scottish National Party seeks to heal internal divisions and strengthen its position ahead of U.K.-wide parliamentary elections expected later this year.

Yousaf, whose pro-independence party has been weakened by a campaign finance scandal and divisions over transgender rights, was brought down by his decision to oust the Green Party from his governing coalition because of differences over climate change goals. He was unable to persuade other parties to back his minority government in Scotland's regional parliament.

With no prospect of victory in two confidence votes that had been scheduled for later this w...