Jerusalem ? Israel’s defense minister quit the Likud Party on Sunday to join Prime Minister Ariel Sharon’s new centrist faction, saying his former party had been hijacked by “right-wing extremists.”

The defection of Shaul Mofaz, one of the most prominent Likud leaders, further marginalized the increasingly hard-line party and gave Sharon added momentum as he prepared to campaign for March 28 elections.

Mofaz’s decision came after weekend polls showed him badly trailing former Prime Minister Benjamin Netanyahu and Foreign Minister Silvan Shalom in the race to become Likud’s candidate for prime minister, but he insisted the party’s direction, and not the polls, were what influenced his decision.

Sharon told aides Sunday that Mofaz called him a day earlier to tell him he intended to leave Likud.

Sharon formed the Kadima Party last month.