In 1961, the Justice Party (AP) was established, claiming to be the successor to the Democratic Party. In the meantime, the National Unity Committee established an interim House of Representatives instead of the Grand National Assembly, in order to prepare a new constitution for Turkey. In the new constitution, the Constitutional Court was to be established, to prevent the government from violating the constitution. The 1961 constitution is widely accepted as to be the most liberal and democratic constitution in Turkish history. Also, the winner-take-all electoral system was immediately abolished, and a proportional representation system was introduced. The new constitution brought Turkey a bicameral parliament, composed of the Senate of the Republic as the upper chamber, and the National Assembly as the lower chamber. The National Unity Committee chairman General Cemal Gürsel was elected as the fourth president of Turkey.