The European Union's (EU) top court on Thursday ruled in favour of Polish consumers who took out mortgages in Swiss francs, allowing them to ask courts to convert the loans into Poland's zloty currency or cancel the contracts.

Changing the terms of the loans, which had become prohibitively expensive after the Swiss franc jumped in value, means Polish banks will have to refund some customers.

"Support may concern some legislation that would allow banks to overcome this problem more smoothly," Kwiecinski told reporters, without revealing details nor saying if this concerns new or existing legislation.

Representatives of the central bank and the KNF financial watchdog were not immediately available for comment.

Kwiecinski also said that the EU court ruling will have strong consequences for banks. Lenders have said the cost could amount to 60 billion zloty (£12.34 billion).

Polish banks are regarded as well capitalized, given the strict domestic capital requirements. Analysts say the banks can brace for future losses by cutting back on dividends or on lending.

Share prices for banks with big Swiss franc-denominated mortgage portfolios recovered some previous losses on Friday, with PKO and Santander's Polish unit both rising 1% while Millennium outperformed the pack with a 4.7% gain.

(Reporting by Agnieszka Barteczko; Writing by Marcin Goclowski; Editing by David Goodman)