A court is due to decide on an appeal over the 30-day pre-trial imprisonment of Russian dissident and Kremlin critic Alexei Navalny on Thursday.
Navalny returned to Russia earlier this month after receiving treatment in Germany following an assassination attempt with the nerve agent Novichok. He was immediately detained upon his arrival and sentenced to pre-trial detention.
Navalny's lawyers hope that the Khimki court near Moscow will free the 44-year-old.
He is accused by Russian prosecutors of violating a previous suspended sentence by travelling to Germany.
Navalny's team called for protests this coming Sunday to go ahead regardless of the court's decision.
Whether the earlier suspended sentence will be converted into a prison sentence, as prosecutors are calling for, will only be decided in a 2 February trial.
Thousands of people have so far taken to the streets across Russia to call for Navalny's release, and more than 3,700 people were detained by security forces while demonstrating last weekend.
On Wednesday, Navalny's Moscow apartment was searched by masked men in uniforms.
A family flat, an apartment where his wife was staying and a studio where the internet show "Navalny Live" is filmed were also searched, Navalny's team said.
Russian media reported that the reason given by security sources for the raids at more than 10 sites was violations of coronavirus hygiene restrictions.