Prime Minister David Cameron\'s plan to legalize gay marriagewill weaken marriage as an institution, the head of the Catholic Church in England said Friday. The Most Rev. Vincent Nichols, who as archbishop of Westminster is the senior cleric in England and Wales, said at a news conference that Cameron wants to \"annex the institution of marriage\" for homosexuals, The Daily Telegraph reported. Nichols said he respects Cameron\'s desire to encourage equality and committed gay relationships. \"But commitment plus equality does not equal marriage and the distinctive nature of marriage is something that is very important to the well-being of society because it is the foundation of family life as we know it and as it experienced by the vast majority of people,\" he said. Civil partnerships have been legal in Britain since 2005. Under Cameron\'s plan, gay couples would be allowed to hold partnership ceremonies in religious facilities starting next year and a commission would study changing the law to allow marriage. The prime minister, who is head of the Conservative Party, argues Conservatives should support homosexuals seeking more stable relationships. The Liberal Democrats, the junior member of his coalition, was the first party to endorse gay marriage.