The Attorney General has guaranteed that anything said by witnesses to the Grenfell Tower Inquiry will not be used to prosecute them over the fire.
Suella Braverman wrote to the inquiry chairman, Sir Martin Moore-Bick, confirming that the Government had accepted the request from staff involved in refurbishing the high-rise block with flammable materials.
Lawyers from firms including the main contractor and architects involved in revamping the 24-storey tower in west London submitted the last-minute bid for the pledge when the inquiry reopened in January, causing proceedings to be delayed.
Without the Government-backed guarantee, many witnesses had threatened to stay silent by claiming the legal right of privilege against self-incrimination.
Survivors' group Grenfell United said it was a "sad day" following the Attorney General's decision to grant an undertaking to the Inquiry.
For all the answers on what the decision means, see the factsheet below.
Mrs Braverman's office said she "had concluded that the undertaking is needed to enable the inquiry to continue to hear vital evidence about the circumstances and causes of the fire. Without it, she has concluded that some witnesses would be likely to decline to give evidence".
In a statement, the Attorney General said: "The undertaking I am providing to the inquiry means it can continue to take evidence from witnesses who otherwise would be likely to refuse to answer questions.
"These questions are important to finding out the truth about the circumstances of the fire. The undertaking will not jeopardise the police investigation or prospects of a future criminal prosecution."
Sir Martin said he had sought the pledge to allow individual witnesses to furnish the public hearings with a truthful account without fear for the future, allowing him to make recommendations based on the fullest body of evidence possible.
The proposed undertaking will cover oral evidence from individual witnesses only and does not mean companies or individuals cannot be prosecuted. Evidence given to the inquiry in written statements or documents can be used against them in any future prosecution, the Attorney General's Office said.
Sir Martin said the Metropolitan Police did not suggest that granting the undertaking would "hamper" its concurrent investigations.
Scotland Yard is carrying out its own investigation into possible crimes ranging from gross negligence manslaughter and corporate manslaughter to health and safety offences over the 2017 fire, which killed 72 people.
The application for protections related to witnesses from firms including external wall subcontractor Harley Facades, main contractor Rydon, architects Studio E, and window and cladding fitters Osborne Berry.
The second stage of the inquiry previously heard that the main designers and contractors involved in the refurbishment appeared to predict that the cladding system would fail in a fire up to two years before the disaster happened.
Hearings in the Grenfell Tower Inquiry will resume at 10am on Monday, an inquiry statement said, after the Attorney General granted the undertaking.
Grenfell United statement in full
"The past few weeks have been very difficult, and this decision still makes us nervous.
"We can't help but worry about how this will impact prosecutions later. It is clear that corporate lawyers are playing every trick in the book.
"The inquiry is about getting to the truth so that lessons are learnt and the Government can make changes. We take part to make sure there will never be another Grenfell and people are safe in their homes.
"But truth at the Inquiry must not come at the expense of justice and prosecutions. For our continued participation, the Government must make sure the inquiry process does not undermine prosecutions. If prosecutions are affected by this decision we will hold the Government accountable.
"Grenfell was a tragedy, but it was not an accident. The people responsible for knowingly encasing our families in a death trap and the people that allowed them to do it must face the full force of the law.
"We expect criminal prosecutions at the end of this, and will not settle for anything less."