Christopher Isham, who has been the Washington Bureau chief at CBS News for more than a decade, will cede many of his duties to focus more intently on coverage around the 2020 election before leaving the company at the end of the year.

In a memo to staffers, CBS News President Susan Zirinsky said Ingrid Ciprian-Matthews, an executive vice president who oversees recruitment and development at the ViacomCBS unit and has worked there since 1993, will serve as an interim head of the bureau while leading the search for its next top executive, along with Zirinsky and Kim Godwin, executive vice president of news.

“We will begin a transition process immediately that gives us the time to maintain our competitiveness at a most challenging time,” said Zirinsky in the memo.

Isham will be the second senior CBS News executive to articulate a departure in recent months. In May, Charlie Pavlounis, the unit’s former chief financial officer, announced he would leave. All the moves are slated to take effect July 6.

The Washington Bureau has taken on new importance for CBS News in recent months. It now houses two of the unit’s flagship programs, “CBS Evening News,” anchored by Norah O’Donnell, and “Face The Nation,” led by Margaret Brennan.

Other changes are afoot for CBS News in the nation’s capital. Ward Sloane, the deputy chief at the Washington Bureau, will be moving into a new role which we will be announcing soon,” said Zirinsky. And Lorna Jones, who has worked as a managing editor, will succeed him in that role. Jones has been in the bureau since 2015, and has been working at CBS News since 2001. when she joined “48 Hours” as a production secretary, moving up the ranks as a producer in several different areas. “With the tremendous pace of news, this is a pivotal time for all of us in the Washington Bureau. I look forward to helping support the next chapter for CBS News,” Jones said in a statement.