Capping rents could force landlords out of the market and make life harder for tenants if it is done too bluntly, the housing charity Shelter has warned.

In a report commissioned by the charity and shared with the Guardian, researchers from the University of Cambridge said “hard rent controls” would remove landlords’ financial incentive to invest in their properties, and lead to poorer quality homes.

A survey of landlords carried out for the report found 31% claiming they would sell all or some of their properties immediately if rents were frozen, meaning less choice for those in the private rented sector.

Researchers also warned of a serious risk that a blunt cap on rents would encourage the growth of a black market not subject to rent regulation.