WASHINGTON (AP) — A federal judge has ruled that former Vice President Mike Pence will have to testify before a grand jury after he was subpoenaed by the special counsel investigating efforts by former President Donald Trump and his allies to overturn the results of the 2020 election.

That’s according to two people familiar with the ruling, who spoke on condition of anonymity because it remains under seal.

The people said, however, that the Pence would not have to answer questions about his actions on Jan. 6, 2021, when a violent mob of Trump’s supporters stormed the building as Pence was presiding over a joint session of Congress to certify the vote.

Pence had argued that, because he was serving in his capacity as president of the Senate that day, he was protected from being forced to testify under the Constitution’s “speech or debate” clause, which is intended to protect members of Congress from questioning about official legislative acts.

The extraordinary scenario of a former vice president potentially testifying against his former boss in a criminal investigation comes as Pence has been weighing challenging Trump for the 2024 Republican presidential nomination.

Pence’s team is discussing whether it will appeal.