NATO's 54th Parliamentary Assembly session in Valencia runs from November 14 to 18. Georgian President Mikheil Saakashvili, who has been actively seeking membership in the Western military alliance, is expected to focus on criticism of Russia's role in the August conflict over South Ossetia.
"Parliamentarians should be free to choose their information sources [on the conflict]. Instead of hearing alternative information, they will be listening to the twittering of Saakashvili," Russian envoy Dmitry Rogozin told RIA Novosti.
He said he had intended to give Russia's account of Georgia's August 8 attack on breakaway South Ossetia and the ensuing five-day war between Russia and Georgia, but that the NATO Parliamentary Assembly's president, Jose Lello, had refused, saying there was not sufficient time to fit him into the session schedule.
Saakashvili will give his speech on November 18. Rogozin said he has refused NATO's invitation to attend the session.
During the August conflict, most Western powers sided with Georgia, accepting Saakashvili's claim that Georgia reacted to military aggression from Russia.
However, Saakashvili's version of events has come under scrutiny since the conflict, and Western rights groups have criticized Georgia's attacks on South Ossetian civilians.
A report released on November 4 by the U.S.-based Human Rights Watch said the Georgian military used cluster munitions in civilian areas of South Ossetia.
Independent observers from the Organization for Security and Cooperation in Europe have said they are unable to verify Georgia's claim that Russia bombarded Georgian villages in the run-up to the conflict. Georgia had based its justification for its attack on South Ossetia on the alleged Russian bombardment.
Saakashvili has also come under pressure in his own country. Around 10,000 protesters gathered on the streets of Tbilisi last Friday, rallying against the president for dragging the country into a costly war that it had little chance of winning.