Housing Minister Alok Sharma has refused to confirm whether the cladding used on the Grenfell Tower was illegal or banned.
Mr Sharma was asked the question at least five times during an appearance on ITV's Good Morning Britain.
Despite confirming evidence suggested the material was "combustible" and "non-compliant" on buildings over 18 metres, he stopped short of declaring it banned.
The minister faced questions as a major security operation continues to remove and check cladding from high-rise flats across England.
Some 60 blocks in 25 local authority areas have so far proven to be potentially flammable in the urgent safety review, with every single sample to have undergone checks failing testing.
Asked by presenter Susanna Reid if a builder putting up a tower block today would be allowed to use the Grenfell type of cladding, Mr Sharma said: "The building regulations are very clear. Any building above 18 metres, this would be non-compliant."
Ms Reid then asked: "When you say non-compliant, do you mean it's banned?"
Mr Sharma replied: "It means that you are not allowed to do it."
Pressed again on whether this meant it was illegal, he said: "Well, you are not allowed to do it, it is non-compliant.
"The regulations are very clear on this point, and clearly the public inquiry has been set up to investigate precisely what happened and we will get to the bottom of this."