The number of MPs supplementing their incomes by acting as landlords has risen by a quarter since the last parliament, with David Cameron and George Osborne among those earning extra money by renting out properties.

The guardian reported almost a third of MPs are now letting out their houses or flats, with 196 declaring rental income on the official register of interests this year. The majority of those are earning more than £10,000 a year from the property, topping up their basic MP’s annual salary of £67,060.

The Conservative party has the highest number of landlord MPs at 128, meaning 39% of Tory MPs are landlords, compared with 26% of Scottish National party MPs and 22% from Labour.

The research reveals a much higher proportion of MPs are landlords than the general adult population, in (2% estomated) to be renting out homes.

The chancellor is also reducing tax breaks for landlords and bringing in an additional 3% stamp duty on second properties in an apparent attempt to slow the buy-to-let boom.

The prime minister’s rental property is thought to be the four-bedroom house in Notting Hill he bought in 2005 for more than £1m, which is likely to have more than doubled in value since. Osborne has rented out a residential property in London since 2011.

Brandon Lewis, the housing minister, who lets a house in Essex that brings in more than £10,000 a year.

The government was further criticised this week when Conservative MPs threw out a Labour amendment to thehousing bill designed to ensure all rented accommodation is safe for people to live in.

18 MPs have a shareholding, interest or directorship in at least one property company.

David Tredinnick, a Conservative backbencher, is the director of Malden Mitcham Properties and declared £22,311.52 of income from his 12 hours work for the company each month. Tory MP James Cartlidge is the founder and former co-director of Share to Buy, a shared ownership company, and maintains shareholdings.