Poles will choose their new head of state next Sunday in a second, decisive round of voting in which Komorowski, candidate of the ruling centrist Civic Platform (PO), is competing against the main opposition leader, Jarosław Kaczyński of the centre-reight.
During the first live debate between the two candidates after the first round of the election, Kaczyński criticised the gas deal with Russia for 10 billion cubic metres (bcm) of gas a year until 2037, which the PO-led government had negotiated.
"It is very risky to sign deals for more than 20 years," Kaczyński said of the agreement, which still needs to be formally signed before it can be enacted.
Poland faces an annual shortfall of some 2.5 billion cubic metres of gas without the deal, but Komorowski said during the debate that Warsaw was eyeing shale gas as an alternative.
"Simultaneously, we need to conduct these negotiations about natural gas and search for shale gas," he said.
"If we find out that we have enough shale gas, we want to have the right to renegotiate the deal with Russia or maybe we will step aside from it."
Poland's first shale drilling will end in several months' time and it will take several years to fully determine how much shale gas there is in Poland, Komorowski also said.
Poland relies on imports for three-quarters of its annual gas consumption. Russia is its main supplier. Diversification has been high on the agenda of consecutive governments.