Speaking to journalists on Sunday, Leonid Pasechnik said that "in the near future a referendum will be held in the republic, where people will exercise their absolutely constitutional right, and give their opinion with respect to joining Russia."

He added that he was "somehow sure that's precisely the way it will be."

The comments come one day after President Biden called for "regime change" in Russia during a speech in Warsaw (before his people swooped in to clarify that he was condemning Russia's efforts to exercise power over the region, not within Russia itself). Later, Secretary of State Antony Blinken clarified that "we do not have a strategy of regime change in Russia."

Still, Biden's comments marked the second time in as many days where the aging American president let it slip that regime change in Russia - and American boots on the ground - might be part of NATO's endgame playbook.

Even if the people of Lugansk clearly choose to align themselves with Russia, there's little doubt that the west will reject the legitimacy of their decision on the grounds of Ukraine being a 'sovereign state'.

Back in Moscow, Russian Senator Andrey Klishas reiterated on Sunday that both Lugansk and Donetsk had the right to seek to join Russia unless such a move would violate their constitutions.

But not all Russian politicians expressed support for an immediate referendum. Leonid Kalashnikov, who chairs the Russian Duma's committee on the Commonwealth of Independent States Affairs, Eurasian Integration and Relations with Compatriots, warned that "now is not the right moment" for holding a referendum in the republic. He added that "you hardly need to bother with such questions when destiny is being determined on the frontline."