The Polish government in mid-June adopted a proposal to set a guaranteed price of PLN 996.60 (EUR 210) per tonne of coal purchased by households.
The lower house of parliament on Thursday approved this plan in a 298-15 vote with 136 abstentions, state news agency PAP reported.
The measure now goes to the Senate, the upper house of Poland's parliament, for further debate.
Under the plan, households would buy coal from importers for no more than PLN 966.60 per tonne, while the rest of the tab would be picked up by the government, according to officials.
The system would cover households, housing cooperatives and associations that use coal for heating, according to Climate and Environment Minister Anna Moskwa.
She has told reporters that each household will be allowed to buy up to 3 tonnes of coal at the guaranteed price.
The government has allocated PLN 3 billion (EUR 635 million) for the programme, according to Prime Minister Mateusz Morawiecki’s office.
The initiative is designed to protect customers from the effects of rising prices of coal in the aftermath of Russia's invasion of Ukraine, government officials have said.