MOSCOW, Jan 20 (Reuters) - Russian-backed separatists in east Ukraine would expect Russia's army to fight with them against Ukrainian government forces if Moscow follows through on a parliamentary proposal to recognise their independence, a pro-Kremlin lawmaker said on Thursday.
Alexander Borodai made the comment after 11 lawmakers proposed that parliament ask President Vladimir Putin to recognize the independence of the breakaway Donetsk and Luhansk regions.
Such a move would mark a major escalation by Russia after weeks of mounting tensions around Ukraine. A Russian military buildup and threatening rhetoric have stoked Western fears of a looming invasion, though Moscow denies any such plan.
Borodai, a former Donetsk political leader who is now a member of the Russian parliament, said the separatists would look to Russia to help them wrest control of parts of the territory they claim that are now held by Ukrainian forces.
"In the event of (the republics) being recognised, a war will become a direct necessity," Borodai told Reuters.
"Russia would have to take on some security responsibilities" and defend the territories, he said, as it did after recognising the independence of two breakaway Georgian regions after a 2008 war between Russia and Georgia.
The separatists took control of a swathe of eastern Ukraine in 2014 in a conflict that continues to simmer and has killed 15,000 people, according to Kyiv. Ukraine has long accused Russia of having regular troops in the region, something Moscow denies.
Borodai, a lawmaker for the ruling, pro-Putin United Russia party, served as prime minister of the self-proclaimed Donetsk People's Republic in east Ukraine at the height of the conflict in 2014. He now leads an organisation of war veterans.
Kremlin spokesman Dmitry Peskov on Thursday responded cautiously to the proposal on recognition, saying he could not comment until parliament had voted on it. The lawmakers behind it are from the Communist Party, which casts itself as an opposition force but actually often backs the Kremlin.
Two sources familiar with government discussions of the proposal told Reuters the idea of recognising the regions was being seriously considered.
But a source close to the separatist leadership said the likelihood of such a move was low because it could provoke punitive measures against Russia, potentially entailing serious economic damage.
Orysia Lutsevych, a Ukraine analyst at Chatham House think-tank in London, said recognition could create a legal pretext for a Russian invasion of Donbass to "protect" it from Ukraine.
She said it would be a "clear step of escalation" requiring a Western response in the form of sanctions against Russia or bolstering NATO forces on the alliance's eastern flank.
