Voters in Poland have started casting their ballots in an election expected to tip the balance of power in parliament in favour of the conservative opposition.

Economic and social issues, as well as the refugee crisis, dominated the election campaign for Sunday's poll.

Surveys showed the opposition conservatives were firmly ahead after running a campaign of anti-refugee rhetoric and welfare promises.

Four polls published late last week placed support for Law and Justice between 32 percent and 40 percent, while Civic Platform trailed with 22 percent to 28 percent of respondents.

It is unclear how many parties - anywhere from three to seven - will gain mandates in the 360-seat Sejm, the lower house of parliament. Voters will also decide about the 100 seats in the Senate, the upper chamber.

However, no matter which of the two main parties comes in first, Poland will be led by a woman. Current prime minister, Ewa Kopacz, leads Civic Platform, while Beata Szydlo is Law and Justice's candidate.

During a television debate last week, Szydlo promised to give more money to families and pensioners, launch a job creation programme for young people and lower the retirement age. The Civic Platform-led government had raised it to 67. 

Civic Platform had made raising the minimum wage a cornerstone of its campaign. Kopacz has sharply criticised the opposition's plans, and claims they will seriously damage the country's finances.

Kopacz's campaign has failed to ignite much voter interest in recent weeks, in contrast to Szydlo, who has proven she knows how to work the crowds.

James Bond approach

When Szydlo became the conservative party's candidate this summer, she chose a James Bond-like approach to introduce herself to fellow party members at a convention to launch the campaign.

"My name is Szydlo, Beata Szydlo," she said. "I have opinions of my own."

Those words were directed toward political opponents who speculated Szydlo was only being put forward as an appealing figure to front the party, while powerful party chairman Jaroslaw Kaczynski pulled the
strings.

The conservative party has taken a tough stance on the wave of migrants and refugees arriving in Europe, warning that the newcomers pose a threat to security and could undermine the social fabric of
Poland.

Although softer in policy and tone on the subject of migrants, Kopacz's government is opposed to binding EU refugee quotas.

Kopacz succeeded Donald Tusk as prime minister one year ago when he was named president of the European Council.

She has struggled to fight the impression among some that she was Tusk's choice because he hoped to maintain long-distance control on government affairs.

Some 30 poles are eligible to vote in the election. Polls are open between 7am and 9pm (06:00-20:00 GMT). Exit polls are expected immediately after voting ends.

Source: Agencies