Prime Minister Theresa May has said there needs to be "a major national investigation" into the use of flammable cladding on high rise blocks.
Mrs May said the probe should encompass all cladding used across the country over the past few decades.
She made the statement at Cabinet as ministers learned every national cladding sample submitted for fire safety checks had failed combustibility tests in the wake of the Grenfell Tower disaster.
Flammable cladding was found on 95 high-rise buildings across 32 local authority areas.
It also emerged today that nine NHS hospital trusts have buildings with cladding similar to that used on Grenfell Tower.
The PM's official spokesperson said the investigation into cladding and its historical use could come as a second phase of the judge-led public inquiry into Grenfell blaze, which claimed the lives of at least 79 people earlier this month.
The spokesperson said evidence suggests the use of the suspect cladding stretches back at least into the last decade.
Grading the cladding material on a scale of fire-resistance, the so-called combustibility assessment determined whether the material meets building regulations.
Communities and Local Government Secretary Sajid Javid, who updated Cabinet on the latest test failures, confirmed schools and hospitals have been asked to send in samples of cladding if they have concerns.
On Monday Mr Javid told the Commons that 1,000 fire doors were found missing from the Camden tower blocks evacuated over the weekend.