By Renee Maltezou
ATHENS (Reuters) - Greek lawmakers vote in the second round of a presidential ballot on Tuesday that could take the country closer to snap general elections and derail talks to end its international bailout accord.
Prime Minister Antonis Samaras, whose term is to end in mid-2016, has offered to bring pro-European independents into the government and hold elections by late next year if they support Stavros Dimas, the only candidate in the race.
But it remains unclear whether the offer will be enough to win the 20 votes from independents and members of the smaller opposition parties he needs to win the final round on Dec. 29.
If parliament fails to appoint a president, a general election must be held by early February, potentially bringing in the leftwing Syriza party, which wants to renegotiate the bailout and write off a large part of Greece's debt.
Spiros Lykoudis, an independent lawmaker who has supported Dimas, believes it would be difficult for the government to win the necessary support after a disappointing first round.
"I don't believe the situation will change dramatically, mainly because, from what they're saying, the opposition parties don't want a president to be elected," he told Reuters.
With financial markets and Greece's European partners watching closely, voting begins at midday (1000 GMT), with the result likely around an hour later. Lawmakers either vote for Dimas or record a blank vote by declaring "present".
While Dimas is not expected to get the 200 votes needed for victory on Tuesday, the result should show whether support for the government has advanced from the first round, when only five independents voted for Dimas, giving him 160 votes.
To become president, he will probably need to wait for the third round when the required super-majority drops to 180 votes, meaning a frantic round of between-vote backroom meetings and telephone calls looms.
Several independents responded positively to Samaras's offer and Greek media calculate that Dimas could garner 169 second-round votes while lawmakers in the ruling coalition said anything over 170 would be a success.
Syriza, whose once-strong opinion poll lead has narrowed in recent weeks, has rejected the government's offer of an accord, saying Samaras feared facing voters.
Two smaller opposition Independent Greeks and Democratic Left, which between them have 22 seats, have also rejected the deal. They are not considered to have tight control over deputies and several may back the government.
(Writing by James Mackenzie; Editing by Tom Heneghan)