Conservative Sauli Niinistoe looks set to cruise to victory in Finland's second round of presidential vote on Sunday, with polls giving him a wide lead over green liberal challenger Pekka Haavisto.

Niinistoe's finance minister experience has lent his candidacy credibility amid the European debt crisis while green liberal Haavisto's openly gay stance appeared to be less popular with older and more traditional Finns.

The most recent public opinion poll credited the National Coalition Party's Niinistoe with 64 percent of support compared to 36 percent for the Green League's Haavisto.

In the first round of voting on January 22 that featured eight candidates, Niinistoe, who survived the 2004 Indian Ocean tsunami in Thailand by climbing a tree, garnered 37 percent of votes and Haavisto 18.8 percent.

"Since the first round Niinistoe has been so strong ... Haavisto's support may not rise above 40 percent," Turku university parliamentary researcher Ville Pernaa told AFP.

Both pro-European candidates agree on most aspects of foreign policy -- one of few areas the president still decides, analysts note.

"The big issues that normally divide the candidates don't exist in this election," Pernaa noted.

However, Niinistoe's long tenure as finance minister from 1996-2003 during which he was instrumental in leading Finland into the eurozone, is giving him the lead over his challenger, particularly in the first round of voting when the eurozone crisis was cited as voters' main concern.

For many Finns, "Niinistoe represents practical economic expertise," Helsinki University political science professor Tuomo Martikainen told AFP.

Even anti-EU candidates who did not make it past the first round have endorsed Niinistoe.

Haavisto has won support from left-leaning voters who feel they cannot vote for Niinistoe, but this group is ultimately marginal, Martikainen said.

Rather, the candidates' sexual orientation was turning out to be a key factor in the polls, analysts said.

The 53-year-old Haavisto has earned the respect of his peers and many members of the public for his openness about his registered same-sex partnership with Antonio Flores, an Ecuadorean hairdresser.

However, some notably older, more traditional-minded Finns see this as a sign of moral degeneration rather than liberalism and tolerance.

Local daily Helsinki News noted, quoting an unnamed foreign ministry official, that "as president, Haavisto cannot visit 77 countries, at least not with Antonio."

"No doubt there are those for whom it is a strange thing for a future president to be living in a registered partnership," Haavisto acknowledged during a recent debate, adding that his objection to military service, his green orientation and vegetarianism might also be "too much for some to swallow."

Niinistoe's dramatic personal experience, including the narrow escape from the tsunami has meanwhile endeared him to some voters.

After a high profile romance, he announced his engagement in 2003 to an ex-beauty queen turned parliamentarian, but that relationship ended just a year later.

He is now married to a press officer from his party who is 29 years his junior.

More than 36.3 percent of an eligible 4.4 million voters have already cast their ballots in advance voting and final results are expected around 2000 GMT on Sunday.

Finland's popular outgoing President Tarja Halonen is stepping down after serving a maximum of two consecutive terms.