The Ulster Unionist Party has come under fire for claiming almost 400,000 people are waiting for treatment in Northern Ireland.
In the Assembly on Tuesday, the party's East Antrim MLA Roy Beggs said one in five people in Northern Ireland were currently on a waiting list for treatment.
The DUP branded the claim "irresponsible and at worst scaremongering" saying the matter was something which should not be used for political gain.
Mr Beggs again repeated his claim on Wednesday morning's Stephen Nolan show.
When asked if he was "double counting" with the 392,000 figure - that there could be the possibility one person could feature multiple times on a waiting list - Mr Beggs denied that was the case: "That's what it appears to be to me.
"We are utilising information that is publicly available. If the [health] minister would publish exactly how many individuals are involved, we'd be able to say exactly how many people there were.
"This is the best information that is available."
Mr Beggs, his party's health spokesman, was asked of the figure was true.
"The main thing to remember here," he said, "is that the number has doubled over this last couple of years.
"I have no way of counting who is on two waiting lists - this is the best information that we have."
Asked if he would admit it wasn't true, Mr Beggs responded: "I don't know.
"I am aware, the numbers on those waiting lists have doubled and I also know there are many people in my constituency that are having to wait too long.
"We are not managing our health service, we are not planning our budget, we are not doing it all in a transparent manner.
"The whole system needs reform.
"And so far the whole Sinn Fein/DUP Executive has refused it."
Asked again about the figure he continued: "What other information is available to MLAs or the public, there is no other measure that we can use.
"When we look at the information available to us it is 392,000 people there is no other way in which we can identify individuals on two different waiting lists. It is the best information that is available.
"That figure is the most accurate and widely used within health services to get the measure of people waiting.
"We used three commonly used waiting lists. We could have used another cancer waiting list, but we didn't use it.
"The government doesn't actually know what the figure is."
Mr Beggs refused to retract the claim until the government "tells us exactly how many people there are".
"What we can say is there are 392,000 people on government waiting lists for out-patients, for in-patients clearly they are two separate lists.
"And a further 96,000 waiting for diagnostics."
Asked if they were different people, he said some may be.
"The key point is the figure has doubled in recent years," he went on.
"Undoubtedly there will be some people who may be waiting on two of the lists."
Also asked how many people had been seen within health service targets, Mr Beggs said he had no way of telling.
"That 392,000 were on the waiting list at that snapshot in time," said Mr Beggs.
"They would have been treated after that point in time and therefore I don't know if they have been treated at the appropriate time or outside that.
Mr Beggs conceded to using the term "cases" instead of people eventually.
"If there are 392,000 cases on the waiting list - and this is the best publicly available information - so at that moment in time they have not been treated.
"Nobody knows if they have been treated the next day or have to wait."
Mr Beggs later claimed that the DUP pledge to spend millions on cutting waiting lists earlier this year was a "cheap election stunt" something the party's health spokeswoman Paula Bradley totally rejected.
The Belfast Telegraph has contacted the Department of Health to ask how many people are currently waiting for treatment in Northern Ireland.