Mexico's Congress voted overwhelmingly on Thursday night to dismiss Andrés Manuel López Obrador, the leftwing mayor of Mexico City, from his post, leaving the country awaiting his likely arrest.

The vote to lift the popular mayor's immunity from prosecution sharply increases political tension in the country. Mr López Obrador, who comfortably leads opinion polls for next year's presidential elections, used a rally on Thursday before the impeachment trial to launch his formal candidacy.