U.S. Sen. Dianne Feinstein of California will appear onstage with a challenger for the first time since 2000 when she squares off against state Sen. Kevin de Leon next week.

The two Democrats plan to appear Oct. 17 in San Francisco for an hourlong “conversation” hosted by the Public Policy Institute of California. That’s more than a week into California’s early voting process.

They’re fighting over whether it can fairly be called a debate.

Feinstein’s campaign calls it one, but de Leon’s team said it’s not truly a debate because the candidates will be engaging with the moderator more than each other and it will not be broadcast in prime time. He’s criticized Feinstein for her yearslong record of not appearing in debates.

“Hardworking Californians, people who work two, three jobs can’t take off in the middle of the day to turn on a livestream and watch this conversation,” de Leon spokesman Jonathan Underland said.

Still, it’s significant for the two to appear on stage together at all. Feinstein, seeking her fifth full term, avoided appearing with her little-known Republican rivals in 2006 and 2012 and handily won both races.

She faces a fellow Democrat Nov. 6 because of California’s primary system that sends the two candidates who receive the most primary votes on to the general election.

De Leon is little-known statewide but has a more robust political background than Feinstein’s past two rivals. He led the state Senate from 2014 to early 2018 and sponsored legislation to limit cooperation between local law enforcement and federal immigration authorities as well as bills to expand California’s use of clean energy.

He’s crafted himself as a more liberal alternative to Feinstein.

But she leads comfortably in polling, is well-known to California voters and has more cash, although she hasn’t run any television advertisements since the primary.

She’s been in the national spotlight in recent weeks for her role in the confirmation battle over Supreme Court Justice Brett Kavanaugh. Feinstein is the top Democrat on the Senate Judiciary Committee. Her campaign touts her seniority and experience in Washington, D.C., as assets to California.

PPIC president Mark Baldassare will moderate the hourlong conversation. Each candidate will be asked an opening question they will get in advance, but neither will have access to the other questions ahead of time, said PPIC spokeswoman Abby Cook.

Baldassare will ask the candidates questions and the goal is to limit direct engagement between the two, although there may be opportunity for rebuttals, Cook said.