WASHINGTON (Reuters) -Ousted U.S. House Speaker Kevin McCarthy said on Wednesday that he will leave Congress at the end of this year, a move that raised anxieties among his fellow Republicans about the path that lies ahead for their narrow and fractious majority. His move came as Congress struggles to move forward on a raft of critically important legislation, including fiscal 2024 spending bills that Congress must adopt by Jan. 19 to avert a partial government shutdown. The task poses a new and perilous test for McCarthy's successor, House of Representatives Speaker Mike Johnson, a Christian conservative with relatively little leadership experience who won the gavel after weeks of bitter Republican infighting.