(CNN) - Rep. Michael Castle of Delaware is expected to end speculation Tuesday on whether he'll run for the Senate next year.
The nine term Republican congressman is scheduled to hold a news conference at 12 p.m. ET in Wilmington where he may announce whether he'll run for public office again.
Castle, a former two-term governor of Delaware, said earlier this year that he was leaning against seeking a tenth term in the House and instead was considering a bid for Senate, or possible retirement.
Joe Biden stepped down from the Senate late last year after his election as vice president. Ted Kaufman was appointed to replace Biden, but has said he won't run for election next year, leaving the seat open.
If Castle, 70, does run for the Senate, he could face off against Biden's son, Delaware Attorney General Beau Biden, who last month returned from a military deployment in Iraq.