The liberal Yakloko Party asked prosecutors to investigate claims by teachers in northeast Moscow, as well as postal employees, that they were pressured for the past two weeks to participate in Saturday's rally, RIA Novosti reported.
"The principal position of the prefecture and prefect Valery Vinogradov is that participation in any public events is fully voluntary," the northeast Moscow prefecture said Friday in a statement posted on its Web site, responding to the accusations.
The city's education department also denied any order was issued to employees, RIA Novosti said.
The rally's organizing committee had acknowledged some people were told to attend, but added it was at the local officials' "own initiative."
The pro-Putin demonstration in Poklonnaya Gora Park, also known as Victory Park, is scheduled for the same time as an opposition rally near Red Square.
The rally comes a month before the presidential election that is expected to return Putin to the presidency for a third term.
State-run polling agency VTsIOM said Friday support for Putin rose 3 percentage points this week to 52 percent, indicating he could win the March 4 election outright and avoid a runoff.
"Putin has a solid lead in the presidential election rating poll, with support for him growing from 49 [percent] to 52 percent throughout the week," VTsIOM said.
Support for Communist candidate Gennady Zyuganov, tied for second with Liberal Democratic Party of Russia candidate Vladimir Zhirinovsky was 8 percent, a drop from 11 percent in a previous survey, the pollster said.
A Just Russia Party candidate Sergei Mironov was at 4 percent, a loss of 2 percentage points. Billionaire Mikhail Prokhorov, an independent, also was at 4 percent, unchanged from last week.
Results were based on a survey of 1,600 people in 46 Russian regions conducted Jan. 28-29. A margin of error was not provided.