Six months after Malaysian Prime Minister Najib Razak stood before the United Nations and urged Muslims worldwide to be moderate in their religion, members of his own party are supporting a law that punishes adulterers with death and thieves with amputation.

Lawmakers from Najib's United Malays National Organisation joined the opposition Parti Islam se-Malaysia to pass Islamic criminal law, or hudud, in the opposition-held state of Kelantan. The move has drawn criticism from other parties in their respective coalitions, while human rights groups say it is an unconstitutional step for secular Malaysia.

UMNO officials are burnishing their Islamic credentials to safeguard support among the ethnic Malay majority after the coalition retained power in 2013 by the narrowest margin since independence. The swing by Najib's party to the right risks worsening race relations at a time when economic growth is forecast to slow.