South Korea’s opposition leader offered Sunday to work with the government to ease the political tumult as officials sought to reassure allies and markets, a day after the opposition-controlled parliament voted to impeach conservative President Yoon Suk Yeol over a short-lived attempt to impose martial law.

Liberal Democratic Party leader Lee Jae-myung, whose party holds a majority in the National Assembly, urged the Constitutional Court to rule swiftly on Yoon’s impeachment and proposed a special council for policy cooperation between the government and parliament. Yoon’s powers have been suspended until the court decides whether to remove him from office or reinstate him. If Yoon is dismissed, a national election to choose his successor must be held within 60 days.