President Vladimir Putin thanked Russians on Thursday for voting in favour of controversial amendments to the constitution that could extend his grip on power, as the opposition and Western leaders voiced criticism over suspected poll violations. Russia’s Central Elections Commission announced early Thursday that nearly 78 percent of voters had cast their ballot in favour of the changes to the constitution that could see Putin, 67, remain in power until 2036. “Thank you very much for your support and trust,” Putin said in televised remarks during which he also warned that modern Russia was still in the process of being formed.