The Government has scaled back the amount of cash it is giving in vouchers via the Green Deal Home Improvement Fund – which go towards insulation – after thousands of householders flocked to take up the “generous” offer.

A whopping £43million worth of vouchers were issued in the first six weeks and well more than £50m applied for, said DECC.

So far 7,925 households in England and Wales have received vouchers under the scheme while 12,200 applications have been received for the vouchers which opened to applications on 9 June 2014.

From Friday 25 July the vouchers for solid wall insulation will be lowered from £6,000 to £4,000 for new applicants.

On Tuesday 5 August flue gas heat recovery units will be removed from the list of approved measures.

Any applications already handed in prior to changes will be honoured at the original rates.

Vouchers have been “flying out of the door” according to MP Amber Rudd, newly appointed Parliamentary Under Secretary of State for Climate Change. She said: “We’re delighted that so many families are already making the most of this very generous offer.

“Changes announced today ensure even more households can benefit from warmer homes using less energy. There’s up to £120 million in the pot this year but it won’t be around forever so act now.”