The chair of the influential housing committee of MPs has urged the government to go further than a voluntary pledge from housebuilders not to exploit buyers with costly leasehold agreements.

Clive Betts, Labour MP for Sheffield South East, wrote to communities secretary James Brokenshire outlining his committee’s concerns around escalating ground rents after the government last month published details of an industry pledge which commits firms to doing away with onerous ‘doubling clauses’ that can result in ground rents soaring exponentially over a short period of time.

Brokenshire announced at the time that more than 40 building firms had signed up to the pledge to do away with what he called “toxic leasehold deals”.