Green campaigners have questioned the United Kingdom's commitment to environmental issues after London pulled the plug on a 1.5-billion-pound ($2.1-billion) flagship initiative aimed at cutting household carbon emissions.

The Green Homes Grant voucher program was launched amid great fanfare last year to encourage homeowners to upgrade the insulation in their homes and therefore use less power for heating. It also subsidized the replacement of inefficient boilers with modern low-carbon models.

The government said on Saturday it will not accept new applications from homeowners after the end of this month.

Ed Matthew, campaigns director at the climate-change think-tank E3G, told the Financial Times the program's demise was a "tragedy that was avoidable".

"There was plenty of demand for the grants but the scheme was plagued by incompetent administration," he told the paper."The reality is that we can't get to net-zero without decarbonizing our homes. A new grant scheme must now replace it which can get grants out the door fast, with long-term funding to give business the confidence to invest."

The government, which hoped the program would create "green jobs" and help combat climate change, claimed on Saturday it was only meant to "provide a short-term economic boost".

The Financial Times noted that the assertion was in contrast to Prime Minister Boris Johnson saying in November that it should continue until March 2022 to "help the country build back greener and ...reach the UK's key target for net-zero carbon emissions by 2050".

Environmental groups had welcomed the program's goal of tackling the problem of carbon dioxide emissions escaping from homes, something that accounts for around one-fifth of the nation's total emissions.

The Green Homes Grant had offered ordinary homeowners up to 5,000 pounds toward the cost of improvements to their insulation and boilers, and low-income homeowners as much as 10,000 pounds.

Critics had noted that there appeared to be a problem with the program's management and with lengthy delays.

Last week, UK lawmakers on the environmental audit select committee described it as "botched (in) implementation" and said "the administration seems nothing short of disastrous".

The BBC said it ended up falling far short of its target of improving 600,000 homes, with only around 60,000 being supported.

Kate Blagojevic, the UK's climate change spokesperson for the environmental group Greenpeace, said nations expect the UK, as host of the United Nations global climate conference later this year, to be at the vanguard of climate initiatives.

"But we cannot expect anyone to think we're a credible leader when our own policies on climate action are going in the wrong direction," the BBC quoted Blagojevic as saying.

The Guardian newspaper said the scrapping of the initiative means the UK no longer has a plan for tackling household greenhouse gas emissions.