By Costas Pitas
ATHENS (Reuters) - Greece's anti-bailout opposition party Syriza appears to be gaining momentum with less than a week before Sunday's election, moving further ahead of the conservatives that lead the coalition government in two separate opinion polls.
Syriza, which wants to renegotiate a chunk of Greek debt and end austerity measures, saw its poll lead grow to 6.5 points on Monday, according to a survey for the University of Macedonia conducted for Greece's SKAI Television, up from a 4.5 point lead shown by the same pollster last week.
Syriza would garner 33.5 percent of the vote, up from 31.5 percent, whereas Prime Minister Antonis Samaras' New Democracy party, which has pushed through unpopular reforms as part of an international bailout, stood unchanged on 27 percent.
A Syriza victory could trigger a standoff with Greece's European Union and IMF lenders and unleash a new financial crisis.
A second survey on Monday, carried out by Alco for the newspaper Proto Thema, put Syriza on 33.1 percent with the conservatives on 28.5 percent, a 4.6 point lead for Syriza compared with a difference of 3.5 points in a poll by the same firm last week.
Alco projected the leftist party would win 147 lawmakers in Greece's 300-seat parliament, just short of an overall majority. That number includes the extra 50 seats the electoral system automatically gives the winning party to make it easier to form a government.
Both surveys indicated that centrist party Potami (River) could play the role of kingmaker if voters deliver a hung parliament, with the political movement created by a journalist-turned-politician coming in third place according to the pollsters.
The leading party must generally receive between 36 and 40 percent of the vote to win outright, though it depends on the share of the vote taken by parties that fail to reach a 3 percent threshold to enter parliament.
Samaras' coalition partners, centre-left Pasok, trailed at 4.5 percent in the University of Macedonia poll.
(Editing by Alison Williams)