Kremlin opponent and Yaroslavl regional duma Boris Nemstov will sue the Ukrainian government for refusing him entry to Ukraine on Friday.
Upon his arrival at Kiev's main airport Borispol, Netmsov was issued with a document stating that he was banned from entering the country. It didn't mention how long he was barred for or provide a reason for the decision, however.
Netmsov said on his Facebook account that the Ukrainian government made the decision because of his unequivocal support for the anti-government protests that have brought parts of central Kiev to a standstill for several weeks.
In 2006, Nemtsov was awarded the Order of Prince Yaroslav the Wise by Ukraine's then-President Viktor Yushchenko for distinguished service to Ukraine.
Nemtsov was an active participant in the 2004 Orange revolution that led to the defeat of the current President Viktor Yanukovych in an election re-run. At the time, Nemtsov publicly supported Yanukovych's main rival Yushchenko, standing on a stage beside him in an orange scarf.