Russian MPs have approved a crucial second reading of a controversial law which could increase the Kremlin's control over parliament.The bill, which is expected to be adopted, would change the way parliamentary deputies are elected. Members of the lower house, the Duma, would be chosen by proportional representation, with parties needing 7% of the vote to get seats. Critics say it will be almost impossible for liberals to be elected.Correspondents say such candidates attract only a small number of votes, but they are seen as important for the development of democracy in Russia.