A Russian court on Tuesday slapped Lyubov Sobol, a key ally of jailed opposition leader Alexey Navalny, with a year and a half of restricted movement for breaching coronavirus regulations this year.

Russia's opposition says authorities have stepped up a campaign of intimidation against dissenters ahead of a parliamentary vote in September, allegations the Kremlin has rejected.

In June, Russia declared Navalny's organisations extremist and barred his allies from running.

Sobol, 33, is a key figure in a new generation of opposition challengers, and had planned to run for parliament.

She was accused of calling for Russians to attend an unsanctioned rally in support of Navalny -- who returned to Russia after being treated for poisoning in Germany -- in January.

Her lawyer Vladimir Voronin said that the court banned Sobol from leaving her home between 10 pm and 6 am as well as from attending mass events and leaving Moscow.

Sobol said on Twitter she was "removed from the courtroom" for filming the judge announcing the sentence.

Fellow activists condemned the verdict.

-A year and a half of restricted freedom for a fictitious case without victims- Navalny's spokeswoman Kira Yarmysh, who is herself currently under house arrest, wrote on Twitter.

Several other opposition figures are awaiting a verdict in the so-called "sanitary case", in which opposition figures were accused of breaching coronavirus regulations at rallies in support of the jailed Kremlin critic.

Sobol rose to prominence in 2019 when she went on a hunger strike after being banned from running in local elections.

She is one of many Navalny allies that have faced pressure at home.

Some of the politician's top associates have left Russia.

Western countries have condemned Moscow's branding of Navalny's organisations as extremist.