Russia's parliament could confirm Vladimir Putin as the new prime minister the day after his protege Dmitry Medvedev is sworn in to replace him as president, the speaker of parliament said on Tuesday.

Putin is stepping down as president because of constitutional term limits. He has said he will serve as prime minister under Medvedev, who will be sworn in on May 7.

Asked by reporters if Putin's confirmation vote could be held on May 8, parliamentary speaker Boris Gryzlov said "Why put it off?" Russia's Interfax news agency reported.

"I think it is quite realistic there will be a situation where senators and deputies will gather (on May 8) and support the candidacy of Vladimir Vladimirovich Putin," the agency quoted Gryzlov as saying.

Kremlin loyalists have a huge majority in the lower house of parliament and Putin is likely to be confirmed with ease.

If the vote is on May 8, it would be unusually quick. Previous presidents taking office have needed several days after their inauguration to have their prime ministerial choices confirmed by parliament.

That schedule would also leave little time for Putin to follow the traditional procedure of coming to parliament and meeting with faction leaders before the vote.

Putin has said he wants to remain influential in Russian politics and analysts have speculated that as prime minister he, not Medvedev, will be the real power in the land.

Russian newspapers, citing sources in parliament, reported on Tuesday that a final decision had not yet been taken on when to hold Putin's confirmation vote. They said the date would be announced by April 14.