On the opening day of of the second phase of the inquiry into the blaze that killed 72 people, Richard Millett QC, the inquiry’s chief lawyer, said that each firm critically involved in the project had attempted to shift the blame.

He said that the “sole exception” was the Royal Borough of Kensington and Chelsea building control department, which accepted its failure in ensuring building work is carried out in accordance with regulations.

Statements from architect Studio E, main contractor Rydon Maintenance and cladding subcontractor Harley Facades revealed each was pointing the finger at the other about who had responsibility for choosing the flammable cladding system.

The Inquiry heard that both the architect, client and facade contractor had discussed using the aluminium cladding system before Rydon was engaged as the design and build contractor.

But Harley Facades claimed it could not be held responsible for choosing the cladding system only its installation contending that Studio E had the task of checking the suitability of the Reynobond panel and Celotex insulation system.

Rydon accepted it was contractually responsible as design and build contractor, but had inherited the design agreed originally between the client Kensington and Chelsea tenant management organisation and Studio E.

It said that under its contracts it had delegated responsibilities for cladding design to Studio E and subcontractor Harley Facades.

Rydon’s legal representative said the matter of what exactly was delegated and when should be “considered carefully by the inquiry”.

The Inquiry was also told that the Reynobond polyethylene-filled panel supplier Arconic was aware the panels being used on the tower were unsuitable and had performed worse in fire tests than declared on safety certificates.

Both Rydon and Harley also criticised PIR board supplier Celotex for making misleading claims about the suitability of its RS5000 insulation board on high rises building, again when it had become clear that there were issues with fire spread.

Harley Facades called on the Inquiry to bring in a cladding expert to set out accepted industry practice on where design responsibility lay between cladding installation contractors and architects.

Its legal representative added that there “was nothing unusual about the external facade system, which was widely used through the cladding design industry.”

Both Studio E and Harley also highlighted the systemic use of the cladding system across the industry, arguing that the specification had become an accepted system with 436 buildings found to be unsafe in the wake of Grenfell.

But the firms giving evidence on the first day were accused of trying to duck responsibility.

Millett said: “Not a single-core participant involved in the primary refurbishment of Grenfell Tower has felt able to make an unqualified submission against its own interests.

“Any member of the public reading those statements and taking them all at face value would be forced to conclude that… nobody made any serious or causative mistakes.

“In every case, what happened was, as each of them would have it, someone else’s fault.”

The inquiry continues today with statements from the cladding system manufacturers and suppliers.