A union has stepped up its campaign to keep fire safety regulations in place across London Underground, on the 19th anniversary of the King's Cross fire.
The Rail Maritime and Transport (RMT) union said rules brought in after the blaze in 1987 should not be diluted.
A government spokesman said new fire safety regulations would lead to an even safer Underground system.
The King's Cross fire broke out under a wooden escalator at the central London Tube station and claimed 31 lives.
RMT general secretary Bob Crow said: "As we remember the 31 victims of the King's Cross fire, we should also remember that it was as a direct result of that tragedy that the Section 12 regulations were introduced two years later.
"It is hugely disturbing that less than two decades after King's Cross, and with the 7 July bombings still fresh in our minds, it remains possible that the strict minimum safety standards could be removed."
A spokesman for the Department for Communities and Local Government said: "We do not accept the views of the RMT.
"Public safety is our number one priority and we believe the new fire safety rules will lead to an even safer underground system.
"We are committed to running the existing regulations in parallel with the new regime so the effectiveness can be seen and we won't be removing the old regulations until that has been demonstrated."
Labour MP John McDonnell has tabled a House of Commons motion urging the government to maintain the regulations.