The issuing of primary medical certificates for disabled drivers and passengers has been suspended due to a court decision in June.
Confirmation has been made in a written reply from the Minister for Finance Paschal Donohoe to Independent TD Denis Naughten.
Deputy Naughten said the decision means "people with a disability are marooned in their home if they don't have access to public transport".
The disabled drivers and disabled passengers scheme provides tax reliefs linked to the purchase and use of specially constructed or adapted vehicles by a person with a disability.
The scheme allows remission or repayment of VRT, repayment of VAT on the purchase of the vehicle and repayment of VAT on the cost of adapting a vehicle.
Those who qualify for the scheme can get some additional exemptions and benefits including an exemption from motor tax, toll road fees and a fuel tax.
In June, the families of two children with disabilities won a Supreme Court appeal challenging a refusal to allow them avail of the tax rebate scheme for specially adapted cars.
The court quashed the refusal of the Disabled Drivers Medical Board of Appeal to grant a medical cert permitting the parents of the two children to avail of the scheme.
In a written question to the Minister for Finance, Deputy Naughton asked for Paschal Donohoe’s plans regarding primary medical certificate application refusals as a result of the court ruling.
There are currently about 170 cases waiting for review by the Medical Board of Appeal.
In response, Minister Donohoe said the Supreme Court decision had raised "complex issues".
He said his officials were examining the judgement in conjunction with the AG’s Office.
In the interim, he said on foot of the legal advice received, it had been proposed that PMC assessments would not continue until the establishment of a revised basis for assessments.
Minister Donohoe expressed regret that the PMC assessments were not taking place.
"I anticipate that the work that is currently ongoing in relation to this matter will provide a proper basis for me to make a decision on the best pathway forward and to address the current legal uncertainty around the scheme."
He added that he would seek to bring clarity to the situation so that PMC assessments can continue based on a "firm legal basis".