Russians vote in parliamentary polls tomorrow amid heavy official pressure to ensure a big turnout and majority for the pro-Kremlin United Russia party, and opposition warnings of "mass falsifications", write Neil Buckley and Catherine Belton.

President Vladimir Putin's decision to head United Russia's ticket has raised the stakes for the Kremlin, turning the elections into a referendum on his rule. Turnout of less than 50 per cent, and less than 60 per cent support for the pro-Kremlin party, will be seen as significant setbacks.