Barratt, Bellway, Berkeley, Bloor Homes, Persimmon, Redrow, Taylor Wimpey and Vistry will all come under scrutiny by the Competition and Markets Authority (CMA).

CMA found evidence during its Housebuilding Market Study, the final report of which was published yesterday, indicating “suspected anti-competitive conduct by housebuilders” relating to “concerns that they may have exchanged competitively sensitive information” including non-public information on sales prices, incentives, and rates of sale.

The watchdog also raised concerns over the quality of new homes.

Sarah Cardell, chief executive of the CMA, said it had opened a new investigation into the suspected sharing of commercially sensitive information by housebuilders, “which could be influencing the build-out of sites and the prices of new homes”.

“While this issue is not one of the main drivers of the problems we’ve highlighted in our report, it is important we tackle anti-competitive behaviour if we find it,” she added.

The CMA said it “has not reached any conclusions at this stage as to whether or not competition law has been infringed”.

The CMA has recommended the government implement a requirement for councils to adopt amenities on all new housing estates. Other recommendations include introducing enhanced consumer protections for homeowners on existing privately managed estates and establishing a New Homes Ombudsman.

Cardell continued: “Housebuilding in Great Britain needs significant intervention so that enough good-quality homes are delivered in the places that people need them.

“Our report is recommending a streamlining of the planning system and increased consumer protections. If implemented, we would expect to see many more homes built each year, helping make homes more affordable.

“We would also expect to see fewer people paying estate management charges on new estates and the quality of new homes to increase. But even then, further action may be required to deliver the number of homes Great Britain needs in the places it needs them.”

Ian Fletcher, policy director at the British Property Federation, said the study reinforced the sector’s call for “a better resourced and more streamlined planning system”.

He said: “The CMA report confirms what many within the industry have long been saying. Namely, that we need a better resourced and more streamlined planning system to deliver not only the homes we need, but vital sustainable economic growth. The report rightly focus on these issues along the effective monitoring and enforcement of local plans.

“Of greater significance for residential is the call to increase diversity of tenure on larger sites – a recommendation of the Letwin Review, which was never implemented. As this review also concludes, housing, such as Build-to-Rent, does not impact sales absorption rates, and therefore a site can be delivered quicker overall with diversity of tenure.”