A £49 million energy scheme expansion has got the green light despite concerns over rising debt and its links to a controversial incinerator.

The Energetik heat network – a council-led scheme set up to provide low-cost, low-carbon heating for residents – will be extended along the east and south of the borough after councillors gave the go-ahead at an extraordinary council meeting on Wednesday.

An extra 4,750 homes and businesses will be connected to the scheme as a result of the expansion, boosting the council’s retained earnings to £90 million, according to a council report.

The report states that expanding the network will lead to greater carbon savings while tackling fuel poverty.

Cabinet member for finance Cllr Mary Maguire (Labour, Palmers Green) told the meeting: “This is a real opportunity to take advantage of cheap loans and grant funds to invest in a company that will drastically improve our environment.”

But opposition councillors refused to back the expansion, which the report reveals will increase the council’s total borrowing to fund the Energetik scheme to £77 million.

Shadow cabinet member for finance Cllr James Hockney (Conservative, Bush Hill Park) accused the council of taking a “socialist approach to taxpayers’ money”, pumping more cash into a “loss-making company”.

Cllr Hockney said it would use energy from the new Edmonton Incinerator, which he described as “belching out toxic pollution affecting families in the poorest parts of our borough”.

Cllr Ayfer Orhan (Community First, Ponders End) claimed the expansion would “move the council towards potential bankruptcy”.

She said residents in her ward who had signed up to Energetik told her it was not good value for money, their energy bills were too high and they were “tied into a product they did not vote for, ask for or want”.

Defending the plans, Cllr Doug Taylor (Labour, Ponders End) compared the project to the Victorians building the railways, pointing out they had to invest in the infrastructure before they could receive income.

He said that while the incinerator exists, the council should look to socialise the benefits through the heat.

“If the incinerator was not there, then we would look for alternative ways of generating heat,” Cllr Taylor added. “To me, this is a great opportunity for the borough.”

After the debate, Labour councillors backed the extra investment and the expansion in the heat network. The Conservatives and Community First voted against.