Russian President Vladimir Putin has signed into law a measure that will increase the country's value-added tax (VAT) from 18 to 20 percent as of January 1, 2019.

Putin signed the controversial measure late on August 3.

The government's proposal to raise the VAT, like its plan to raise retirement ages, has angered the Russian public, which overwhelmingly opposes both measures.

The approval rating of the ruling United Russia party has fallen by 16 percentage points since the plans were announced at the beginning of this year, according to the All-Russia Center for the Study of Public Opinion (VTsIOM).

Just 35 percent of Russians polled in late July said they would vote for United Russia if elections were held now.

Support for the Communist Party, which has organized opposition to the measures, has increased to 15.6 percent.

