SEOUL and LONDON — Lawmakers and members of South Korea’s main opposition party gathered in Seoul on Wednesday to call for the resignation of President Yoon Suk Yeol following a night of political chaos sparked by his televised declaration of martial law.

“If President Yoon does not step down immediately, we will immediately begin impeachment proceedings in accordance with the will of the people,” the opposition Democratic Party said in a statement. “We will fight to the end together with all the people to protect the democracy and constitutional order of the Republic of Korea.”

The president said as he declared martial law that the measure would be necessary due to the actions of the Democratic Party, a liberal coalition that Yoon accused of controlling parliament, sympathizing with North Korea and paralyzing the government.

The declaration included banning political activities, including rallies and protests. Yoon also called for a stop to the “dissemination of fake news” and the manipulation of public opinion. All press would have been controlled by the state under the declaration.

The move sparked protests and — just hours after the declaration — the National Assembly voted early Wednesday morning local time to demand that the president lift the martial law order. A majority of parliament voted to lift the decree requiring that it then be lifted, under the South Korean constitution.

Following the National Assembly’s vote, Yoon said he withdrew the troops that had been deployed to carry out martial law and “will lift martial law as soon as we have a quorum in the cabinet.”

The State Council then convened to vote to officially lift it.

The Presidential Chief of Staff Jeong Jin-seok and nine other senior presidential secretaries announced their resignations, the South Korean presidential office told reporters Wednesday morning.

This is a developing story. Please check back for updates.

ABC News’ Ellie Kaufman, Dave Brennan and Meredith Deliso contributed to this report.