Landlords are warning that new laws on tenant evictions in Scotland could cut the number of rental homes.
Emergency powers granted during the Covid pandemic required landlords to seek approval for evictions from a tribunal. MSPs are due to decide whether this should be made permanent.
The Scottish Association of Landlords said members would "lose confidence" and sell their homes if it goes ahead.
The Scottish government said a tribunal process helps prevent homelessness.
The final stage of the Coronavirus (Recovery and Reform) Bill will be debated in the Scottish Parliament on Tuesday.
The Scottish Association of Landlords, the National Farmers' Union of Scotland, the National Trust for Scotland and Scottish Land & Estates claim the proposals could backfire.
The organisations said up to one in five landlords could withdraw from the market, with rental homes already in short supply.
John Blackwood, chief executive of the Scottish Association of Landlords, said: "We are appealing to our parliamentarians to think again.
"There is a tried and tested eviction process which already works well and protects tenants and landlords.
"There is a very real danger that if this goes ahead landlords will lose confidence and simply sell homes at a time when they are in great need."
Sarah Jane Laing, chief executive of Scottish Land & Estates, said: "Whether you are a landlord with a single buy to let flat or someone with multiple properties, the prospect of not being able to regain possession of the home you own scares landlords, driving them from the sector and reducing availability of homes for tenants."
The Scottish government said it would continue to seek improvements in the sector to ensure tenants are treated fairly and can access good-quality properties.
A spokesperson said: "Over the last 20 years, there have been a range of necessary changes to the private rented sector aimed at improving quality and accountability.
"Although stakeholders have often warned that such changes would lead to a reduction in supply of private rented homes, the private rented sector has more than doubled over that time.
"Good landlords recognise the case for keeping tenants in their homes where possible, so adding a final check from the tribunal will support responsible management, recognise financial and other pressures that tenants can face and help prevent homelessness."