Housebuilders are weighing on trading in London following this morning's announcement that the Competition and Markets Authority (CMA) has opened an investigation following evidence that the sector's biggest players may be sharing commercially sensitive information.

The watchdog's "fundamental concerns" are a mix of vindication and potential reprobation for a sector which is going through a period of significant upheaval as rising interest rates have undermined buyer confidence at the same time as costs have significantly increased. In Scotland this led to the collapse earlier this year of Stewart Milne, while Elgin-based Springfield Properties has said it will no longer be taking on affordable housing contracts due to "build-cost inflation".

On the positive side of the CMA coin, the competition regulator has concluded that the blame for the slow delivery of new homes which have habitually missed targets is largely down to a planning system that it describes as protracted, unpredictable, and under-resourced.

READ MORE: Housebuilder Stewart Milne collapses, jobs lost

This comes as no surprise to anyone within the industry, which has long complained of unnecessarily onerous hurdles in the planning permission system. The CMA is also of the opinion that the industry’s use of landbanks - where it has been suggested that the stockpiling of land is artificially slowing delivery of new homes - is in fact a consequence of the sluggish planning process in that it makes sense to carry multiple years’ worth of land on the balance sheet if planning takes years to complete.

Housebuilders will be relieved that their strategy has avoided this blame, but the other headline that the industry's leading players may have shared information regarding pricing, incentives and sales rates is more troubling.

This has not been named as a primary factor in the under-delivery of new homes, but fines could be levied if firms are found to have broken the law. Along with accusations of poor build quality that could potentially need redressed, this could trigger the degradation of profit margins.

The probability of this outcome is far from guaranteed. How strong a conclusion the investigation comes to, and what impact this will have on builders, remains to be seen.