The closure of a scheme which pays householders for installing energy saving measures could have left consumers out of pocket, it has been warned.

The Government has announced the closure with immediate effect for applications to the Green Deal Home Improvement Fund, which provides cashback of up to £7,600 for installing measures such as new boilers and solid wall insulation.

The move came after a surge in applications over the last two days which meant the £120 million budget for the scheme, which opened in June, had been reached.

Earlier this week the Government announced that after Friday, payments for installing solid wall insulation would be cut from up to £6,000 to up to £4,000.

All applications received before the fund closed that met the criteria for receiving money would be honoured at the original rates, the Government said.

But there were concerns that people who had paid £100 for a "Green Deal" assessment of their homes to qualify for the cashback scheme, but had not yet registered, would lose out.

The closure was also labelled as "another setback" for the energy efficiency industry which has seen installation of measures such as insulation decline steeply as a result of cuts to home energy saving programmes.

Energy minister Amber Rudd said: "The Green Deal Home Improvement Fund is a world first and in a short space of time it has proved extremely popular.

"We were always clear there was a budget which is why we encouraged people to act quickly.

"As a result, thousands more families will now benefit from Government help to have warmer homes which use less energy."

But shadow energy and climate change minister Jonathan Reynolds said: "This is a shocking act of incompetence by Government ministers.

"A fund that was supposed to last the year, and compensate for the cuts to energy efficiency measures announced last December, has run out after just six weeks.

"It will leave many customers who have paid £100 for a Green Deal assessment out of pocket, with little prospect of them having the work they were promised done, and an insulation industry in despair at the stop-start nature of this Government's policy.

"We have always said this was the wrong way to make pay-as-you-save energy efficiency work. The Government must now provide clear answers on how they will resolve the mess they have created."

He said he was writing to the chairwoman of the Public Accounts Committee, Margaret Hodge, asking her to investigate the situation.

Richard Twinn, policy and public affairs officer at the UK Green Building Council, said: "The sudden and immediate closure of this fund is another setback for the energy efficiency industry because companies have specifically geared up to market and deliver through this scheme.

"These constant changes are not helpful to industry. We now need urgent clarity as to whether Government will bring forward any more money to ensure continuity of Green Deal work.

"This does demonstrate that we need long-term drivers, not short-term pots of cash, to avoid this continual cycle of boom and bust."

The Green Deal Home Improvement Fund was introduced in the wake of low take-up of flagship energy efficiency scheme the Green Deal, in which providers meet the upfront costs of installing efficiency measures and householders pay the money back from savings they make on their energy bills.