The chief of the Madrid regional government, once seen as a rising star who could become prime minister of Spain, resigned on Wednesday after a website posted video that appeared to show her being detained for shoplifting — the latest in a series of blows to the governing People’s Party.
Cristina Cifuentes, 53, president of the Community of Madrid — roughly equivalent to the governor of a state — had been under pressure to step down for weeks, since separate reports said that she and another prominent figure in the People’s Party had received master’s degrees without doing the necessary work.
Ms. Cifuentes said at a hastily convened news conference on Wednesday that she had intended to resign even before the news website Okdiario.com posted an article about her having been detained by a security guard in 2011 for shoplifting facial cream. The site also posted a video of the episode.
The article said that Ms. Cifuentes had then paid for the items, and the case was not reported to the police.
“I leave with my head held high,” Ms. Cifuentes said at the news conference, adding that she felt she had done her job well. “I leave with a bitter feeling from a personal point of view,” she said, “but I leave very proud, I leave very satisfied.”
Polls have shown the popularity of Prime Minister Mariano Rajoy and his People’s Party flagging, though the next general election could be more than two years away. The party held a majority in Parliament from 2011 to 2015, but elections in 2015 and 2016 gave no party anything close to a majority, and Mr. Rajoy struggled for months to form a government.