LONDON, England: The large British energy firm E.ON Next has delivered an apology after sending warm socks to 30,000 customers with a note to reduce the temperature in their homes.

They also said that lowering heat in homes would reduce CO2 emissions.

The socks were sent to customers who had participated in an "energy saving campaign" last year, The Guardian reported.

However, the timing of sending out socks raised eyebrows, coming in the midst of U.K. households facing greatly increasing energy bills because of a combination of cold weather, nuclear plant outages in France and reduced gas flow from Russia.

Officials have said that British consumers will pay some $1,075 more to heat and light their homes this winter season, according to Bank of America.

In response to criticism for the socks promotion, E.ON Next delivered an apology on Twitter, saying, "If you recently received a pair of socks from us, we would like to say we are incredibly sorry for how we have made some people feel..In light of the seriousness of current challenges that many people are facing, this mailing should have been stopped and we are sorry."

After receiving the socks, angry customers responded on Twitter.

"I don't want your cheap nasty free socks I want cheaper utility bills please," one user tweeted.

"Seriously, energy prices are going up," another user tweeted. "...What the bloody hell."

Meanwhile the opposition Labour Party has called upon the government to impose a windfall tax on companies pumping oil and gas from the North Sea. Labour party officials claim such a tax could reduce the average energy bill by about $272.

Another major energy supplier, OVO Energy-owned SSE, faced the wrath of customers after sending an email to customers encouraging them to cuddle with their pets and eat "hearty bowls of porridge" to stay warm this winter.