Tomorrow the country prepares to mark the fifth anniversary on Tuesday of the Grenfell Tower disaster when 72 people died as fire tore up a tower block wrapped in flammable cladding.

Holyrood has so far received £97 million from the UK Government to deal with the crisis, with a further £300m expected, but, based on new estimates, costs revealed in The Sunday Post show that ministers now believe the total cost will be more than double than original estimates.

The Scottish Government said initial assessment work was progressing along with negotiations with developers, but confirmed to the newspaper: “The total cost of assessment and remediation is estimated at circa £1bn”.

About £240,000 has been spent assessing the risks and work necessary at several high-rise blocks.

But it was reported that no survey reports have so far been completed, with 123 applications for free assessments already lodged.

It previously emerged that more than 400 buildings, including highrises and schools, have potentially deadly material on them.

Nearly 300 other Scots buildings, including 244 schools, nine independent schools, five hospitals, one prison, five hotels, and seven care homes were also found to contain high pressure laminate (HPL) panels, which safety experts have raised serious concerns about.

It is feared the number of care homes with HPL could be even higher.

Thousands of flats in Scotland are also believed to be wrapped in flammable materials.

John Mckenzie, regional secretary of the Fire Brigades Union in Scotland, said the work to identify and resolve building safety issues has been “disgracefully slow”.

He added: “Holyrood and Westminster need to work together to sort this building safety crisis, including committing to funding remediation works immediately and recovering the funds from those responsible for the problems later.

“Until this happens, the public and firefighters will continue to be at risk.”

Housing Secretary Shona Robison told The Sunday Post: “This week we will be remembering those who lost their lives in the tragic Grenfell fire in June 2017. We are taking priority action to prevent another such tragedy occurring.

“We have agreed with some of the country’s largest housing developers to work together to address cladding issues as part of our new Scottish Safer Buildings Accord, giving affected homeowners a clear path to ensuring their homes are safe. Formal principles for the accord are to be agreed shortly.

“We are committed to providing support and remediation where there is a risk to life due to unsafe cladding systems on external walls. The Single Building Assessment (SBA) programme is carrying out fully funded safety assessments to determine which properties have a fire safety risk. The SBA process will not leave buildings with dangerous cladding.”

The Scottish Government said developers will be expected to share the rising burden and that it would get tough on those who refused to play ball saying: “The accord is being developed in collaboration with developers to ensure we have an agreed approach that works for Scottish homeowners.

“However, we will make full use of the powers that are available to us and, if necessary, legislate, if any developers do refuse to participate.”

Housebuilder representative body Homes for Scotland said it was working hard to resolve cladding issues. It said: “We are committed to working with its members and the Scottish Government to develop a Scottish Safer Buildings Accord.”

The Scottish Government insisted its priority was to help homeowners assess their properties free of charge through its Single Building Assessment pilot and said money has now started to be paid out for safety checks.