The federal government wants to delay by two years its deadline requiring all new light bulbs sold in Canada to be energy efficient.

A newly published notice says the current deadline in 2012 would be pushed off by two years to allow time to allay concerns from consumers about new light bulbs.

Canadians have the next 75 days to comment on the proposal.

John Baird, then Canada's environment minister, announced the ban with great fanfare in April 2007, citing it as a demonstration of the Conservative government's commitment to fighting climate change.

The new notice, dated March 24, says the proposed delay would cost Canadians about $303 million to 2020 in lost energy efficiencies as the older bulbs continue to draw higher levels of electricity.

The change would also put about 13 megatonnes more greenhouse gases into the atmosphere.

Delaying the deadline for the new energy-efficient bulbs would also put Canada between one and two years behind the earlier schedule set in the United States.

California and British Columbia have already imposed the new standard for energy-efficient light bulbs, and Ontario is considering the same.

Consumers have raised concerns about one of the most common energy-efficient bulbs, compact fluorescent lamps. These devices contain small amounts of mercury and are not readily recycled.

Environment Canada is working on regulations that would compel manufacturers to ensure the mercury-containing lamps can be recycled.

"Canadians have expressed concerns about certain aspects of the minimum energy performance standard for light bulbs," says the notice from Natural Resources Canada.

"This amendment proposes to delay the effective dates for these wattages by two years in each case in order to enable Canadians to better understand the benefits of the standards, the alternatives that will be available to them and to allay their concerns."

The proposed new deadline would require efficient 75-watt and 100-watt bulbs on Jan. 1, 2014, and 40-watt and 60-watt bulbs on Dec. 31, 2014.