The Residential Landlords Association (RLA) is threatening Oxford Council with a judicial review of its landlord and letting agent accreditation scheme.
The organisation says the scheme is 'discriminatory' and 'unlawful' and it will pursue legal action if the authority does not take action.
The concerns are outlined in a letter opposing the scheme which the organisation says breaches European Directives.
All landlords of Houses in Multiple Occupation (HMO) in Oxford are required to obtain a licence to legally let their property.
However, the RLA's concern centres on the fact that landlords who are accredited by Oxford Council have the ability to obtain a longer licence than those who are not.
According to the RLA, the longer HMO licences provide financial and practical benefits for accredited landlords.
The landlord authority also takes issue with the requirement for landlords to attend training sessions in order to become accredited and subsequently benefit from a longer HMO licence.
It says this condition discriminates against landlords who operate in Oxford but live outside of the city. It claims this is a breach of the EU Service Directive which states that accreditation and licensing 'cannot be provided in a way which discriminates based on country of establishment'.
The letter, penned by RLA policy officer Samantha Watkin, also outlines concerns relating to collection of personal data.
The RLA is now calling on Oxford Council to review its licensing and accreditation requirements as a matter of urgency
"It is very concerning that there are so many apparent illegalities in Oxford City Council’s accreditation scheme," says David Smith, RLA policy director.
"The RLA strongly urges the local authority to review the scheme and would welcome the chance to meet with council representatives to discuss our concerns further."
In 2018, the RLA threatened Great Yarmouth Borough Council with a judicial review due to serious concerns with its selective licensing scheme.