The upper house of Russia’s parliament on Wednesday overwhelmingly backed legislation that is expected to be used to ban allies of jailed Kremlin critic Alexei Navalny from running in elections. The bill approved by the Federation Council would make it impossible to run in elections for leaders, sponsors and rank-and-file members of “extremist” organisations, a designation being considered for Navalny’s organisations. A Russian court is considering whether to designate his political network an “extremist” organisation and could make a decision as early as next week. Kremlin critics say Russian authorities are widening a crackdown on the opposition ahead of parliamentary elections in September. A total of 146 senators backed the legislation, while one voted against and one abstained. The bill will now have to be signed by President Vladimir Putin to become law. The legislation could affect not only senior members and activists of Navalny’s political network but potentially tens of thousands of Russians who supported its work with donations. Leaders of such groups will not be able to run in parliamentary elections for five years while members and those who helped finance their work will be banned from running for three years. Russian authorities had for years tolerated opposition groups including Navalny’s political movement but Kremlin critics say authorities are moving to remove any vestiges of dissent. Navalny, who barely survived a near fatal poisoning with a Soviet-designed nerve agent last summer, was imprisoned for two-and-a-half-years on old embezzlement charges in February.