A coalition of landlords is seeking legal advice over emergency laws freezing rents and banning evictions until at least April next year.
MSPs passed the cost-of-living legislation in just three days last week, back dating the rule to the start of September.
A provision in the law will allow landlords to raise rents by up to 3% if their property costs increase, provided it is no higher than 50% of the rise in costs.
But a coalition of landlords and letting agents has now announced plans to seek a legal opinion on the legislation, assessing if it breaches the human rights of landlords.
The coalition – which includes the Scottish Association of Landlords (SAL), Propertymark, the National Residential Landlords Association (NRLA) and Scottish Land and Estates (SLE) – has instructed Lord Davidson KC to deliver an opinion.
‘Tough time’
John Blackwood, chief executive of the SAL, said the action is being taken “with a heavy heart”.
He added: “This is a tough time, but that does not excuse ill-designed legislation that may be the final straw for the private rented sector.
“We are gravely concerned that in a bid to do something to help tenants, the Scottish Government have forgotten the underlying stresses in the private rental sector that we have been warning about for years.”
Ben Beadle, NRLA chief executive, warned the legislation will worsen a supply crisis in the private rental sector.
“A viable and thriving private rental sector is vital to a healthy housing market,” he said.
“Sadly, the actions of the Scottish Government damage this objective and will ultimately hurt tenants the most.”
A spokesman for the Scottish Government said the new law addresses the cost-of-living crisis by increasing protection for tenants.
“The measures will apply initially until March next year,” the spokesman said.
“We will keep their impact on the wider property market under review during that time.
“The legislation has been carefully designed to balance the protections that are urgently needed for tenants with important safeguards for those landlords who may also be impacted by the cost crisis and face financial hardship.”