Mike Pence subpoenaed by special counsel overseeing Trump probes: Sources

Former Vice President Mike Pence has been subpoenaed by the special counsel overseeing probes into former President Donald Trump, according to multiple sources familiar with the matter.

Sources told ABC News that the subpoena from special counsel Jack Smith requests documents and testimony related to the failed attempt by Trump and his allies to overturn the 2020 election, which culminated in the deadly Jan. 6 attack on the U.S. Capitol.

The subpoena follows months of negotiations between federal prosecutors and Pence's legal team.

Smith was appointed in November to oversee the investigation into Trump's potential mishandling of classified documents after leaving the presidency and obstructing the government's efforts to retrieve them -- as well as a separate probe into efforts by Trump and his allies to overturn the results of the 2020 election.

The move will be seen as a major escalation of Smith's probe into efforts by Trump and his allies to overturn the election, and suggests that Smith's investigation has entered a more advanced stage.

It's not immediately clear to what extent the former vice president might seek to invoke claims of executive privilege over the information sought by Smith, which could set up a potentially lengthy and contentious legal battle with no clear modern precedent.

A spokesperson for Pence did not respond to a request for comment by ABC News. The special counsel's office declined to comment.

A spokesperson for Trump also did not immediately respond.