More than 500,000 Poles took out home loans in Swiss francs mostly in 2007 and 2008, hoping to benefit from low interest rates.

However, the zloty has significantly fallen since then, partly due to a move by the Swiss National Bank to scrap its cap on the franc's exchange rate in January, trapping Polish owners in homes valued well below their zloty market prices.

In September, the Dziennik Gazeta Prawna daily reported that President Andrzej Duda wanted banks' clients to have the right to convert the mortgages at the rate from when the mortgage was taken, citing unnamed sources.

"We are working on the project to have a reasonable character, so that it really helps those who took mortgages in francs and are in a difficult situation," Andrzej Duda told private broadcaster TVN24.

Poland faces parliamentary election on Oct.25 and the main opposition party Law and Justice (PiS) is tipped to win the parliamentary election.

Duda has only been in office since May, when backed by PiS, he was a surprise winner of a presidential election.

"We are in talks and there are other solutions, much more of a compromise than those which were in the parliament. One has to find a solution somewhere in between. There are many ideas, I hope we can work out a solution that would be acceptable," Duda said.

Initially parliament had debated a proposal that would have divided the conversion costs equally between the banks and their clients, but this was unexpectedly amended so that 90 percent of costs were on the banks.

But this proposal was rejected by the upper house of parliament.

The mortgage conversion bill sparked protests from some foreign parent banks. They have said they would seek compensation for any losses incurred as a result and that such legislation infringes on Poland's international investment protection agreements.

(Reporting by Agnieszka Barteczko and Anna Wlodarczak-Semczuk; Editing by Raissa Kasolowsky)