The OFT wants to see if the £700m market is restricting the entry of new competitors, limiting consumer choice or keeping prices artificially high.

The watchdogs are keen to discover any problems ahead of a planned boom under the Government’s Green Deal.

The OFT has received complaints claiming that agreements between businesses at different levels of the supply chain can lead to competitors being unable to source as much insulation as they want, thus restricting supply to consumers.

Last year, the Consumer Direct advice service received nearly 3,000 complaints about solid and cavity wall insulation.

Nisha Arora, Director in the OFT’s Services, Infrastructure and Public Markets Group, said: “The Government’s proposed Green Deal and Energy Company Obligation policies are likely to increase the take-up of energy-efficiency measures, so it is important that we examine the home insulation market now to ensure that it is working well for consumers.”

Further information on the evidence the OFT would be interested to receive and how to submit it are available here