By John Stonestreet
ATHENS (Reuters) - According to most of the two dozen-plus opinion polls published in Greece this month, Sunday's national election contest between Alexis Tsipras' leftist Syriza and Vangelis Meimarakis' conservative New Democracy will go down to the wire.
But a look at the recent track record of polling firms in Greece and elsewhere in Europe suggests it would be unwise to rule out a significant win by one or other party.
Britain, Poland, Denmark and even Greece itself have left polsters red-faced.
In Britain, polls called the result of May's national election badly wrong. They had converged to suggest Prime Minister David Cameron's Conservatives and Ed Miliband's Labour Party were tied or within a point or two of each other on about 32 or 33 percent.
In the event, the former won 37 percent and the latter 31 percent.
"I would not be surprised if the Miliband/Cameron effect replicates itself in Greece and the conservatives do a bit better than expected," said veteran independent political analyst Theodore Couloumbis.
He says Meimarakis' willingness to consider teaming up with Tsipras, an alliance the former prime minister has rejected, could be a decisive factor, though he would not expect a swing of the scale to give one single party a parliamentary majority.
Days after the British vote, the miss by Poland's pollsters was that big, however. They gave incumbent Bronislaw Komorowski a lead of around 10 points going in to first-round presidential elections, in which he finished second.
In June national elections, Danish surveys missed the rise of the Eurosceptic centre-right People's Party, which they placed third but which finished second.
Their Greek counterparts did better in January, picking Tsipras as the national election winner.
But they blotted their copy books badly in July, when they tipped voters to back the country's third bailout in a referendum. The resulting 'no' was resounding - though Tsipras signed the agreement anyway.
Adding to the variables this time around is the large contingent of undecided voters, around one in 10 of the electorate, and Couloumbis is certainly not ruling out another Tspiras win.
"There is a lot of uncertainty... It is anybody's guess who is going to come first," he said.
(Editing by Jeremy Gaunt)