Tymoshenko, who served as President Viktor Yushchenko's first prime minister before being replaced by Yuriy Yekhanurov, said natural gas prices for Ukrainian households have been raised twice, and currently stand at $81 to $88 per 1,000 cubic meters.
"We at the Supreme Rada are ready to disclose the real cost of natural gas that is produced in Ukraine, because it is Ukrainian gas that is supplied to households," Tymoshenko said.
She said her coalition will call for the creation of a special inquiry commission to investigate the circumstances behind the gas price hikes for Ukrainian consumers.
The price of natural gas has been a contentious issue with Russia during western-leaning President Viktor Yushchenko's time in office since 2004. It is also an important factor in Ukraine's economy, which is driven largely by the fuel-intensive heavy industry.
Ukraine currently imports a mixture of Russian and Turkmen natural gas at $95 per 1,000 cubic meters. The price formula is based on a European rate of $230 for Russian gas and $60 for the Central Asian republic's gas. But Russian energy giant Gazprom agreed to a 50% price rise, to $100 per 1,000 cubic meter, for its supplies from Turkmenistan this week.