WARSAW: Poles vote in an election on Sunday that could end nearly a decade of economic and political stability in the country of 38 million, bringing to power a conservative, eurosceptic party whose policies diverge from many of Poland's European allies.

If opinion polls are correct, the ruling Civic Platform (PO), a pro-market, centrist grouping in power for the past eight years, will lose to the conservative Law and Justice opposition party (PiS), run by the twin brother of late president Lech Kaczynski, Jaroslaw.

Most polls show PiS as the frontrunner on more than 30 percent, while PO is second with just over 20 percent. Several small parties are also running, spanning the political spectrum from ultra-right to liberal and extreme left.

Distrustful of the European Union and an advocate of a strong NATO hand in dealing with Moscow, PiS opposes joining the 'euro zone' in the near future, promises more welfare spending on the poor and wants banks subject to new taxation.

It also opposes the relocation of migrants from the Middle East to Poland, arguing they could threaten Poland's Catholic way of life - raising the prospect of tensions with the EU on the issue.

On the campaign trail, Kaczynski and other PiS leaders have sought to tap into anger that the economic success is not more evenly shared out and into nationalist sentiment fanned by immigration fears, particularly among young voters.

"If (PO) maintains power, if we don't manage to take it from them, things will be much worse than before. You may say things cannot get worse. Things can always get worse," Kaczynski told supporters during a rally in Lublin, some 80 km (50 miles) from the Ukraine border.

Poland has seen its economy expand by nearly 50 percent in the last decade and is the only EU member not to experience recession after the 2008 financial crisis. But pockets of poverty and stagnation remain, particularly in the east.

"There is a broader phenomenon of a return to national, religious, community values being seen all across Europe," said political analyst Aleksander Smolar.