Mujib came to office with immense backing from India, and public popularity, but had great difficulty transforming this popular support into the political strength needed to function as head of government. The new constitution, which came into force in December 1972, created a strong executive prime minister, a largely ceremonial presidency, an independent judiciary, and a unicameral legislature on a modified Westminster model. The 1972 constitution adopted as state policy the Awami League's (AL) four basic principles of nationalism, secularism, socialism, and democracy.