Republican Kari Lake officially filed paperwork with the Federal Election Commission to run for the U.S. Senate.
The former TV newscaster and failed gubernatorial candidate seeks the seat held by incumbent Kyrsten Sinema. The independent has yet to formally announce her own campaign plans.
Democratic Rep. Ruben Gallego is also running. Lake's entrance sets up what will likely be a highly competitive three-way race.
Lake previously ran for governor last year and has frequently aligned herself with former President Donald Trump.
She’s scheduled to hold an event next week where she’s expected to formally announce her candidacy.