A planned ban on high-powered rifles has been dropped amid pressure from some Conservative and DUP MPs.
The ban on .50- or higher-calibre weapons was initially included in the Offensive Weapons Bill, driven by concerns over the potential for black market trading in such weapons.
But an amendment tabled by Home Secretary Sajid Javid removing the proposal has now been backed by MPs.
The decision has been described as "staggering" by MP Louise Haigh.
"Senior officers have warned the police have no known protection against these destructive weapons and yet ministers have trooped through the lobby to remove this ban from their own Bill," Labour's Shadow Policing and Crime Minister added.
Speaking in the House of Commons, she accused the government of having "watered down" the bill's proposals, saying it had "rolled over" in the face of its backbenchers.
Independent MP John Woodcock echoed her words, saying the government was prioritising party politics over national security.
'No danger to the public'
Almost 70 MPs had backed an earlier amendment to the bill to drop the ban before Mr Javid's intervention on Friday.
They said they wanted to allow sports shooting enthusiasts to continue to use "high energy rifles" if they have installed enhanced security measures.
Critics of the proposed ban also argued the weapons were not used in serious crime, with Conservative Jonathan Djanogly, who is chairman of the British Shooting Sports Council (BSSC), telling fellow MPs they are too heavy and expensive.
Conservative MP Sir Geoffrey Clifton-Brown, who put forward the earlier amendment, added the rifles "do not pose a danger to the public".
MPs were also being asked to consider strengthening legislation around air rifles, including requiring guns be kept in a locked cupboard, with the key kept separately.
Labour's David Hanson, who tabled the clauses, said the change was needed to improve safety.
The former minister cited the case of a 13-year-old constituent, George Atkinson, who was killed in a "tragic" air rifle accident. The weapon had not been locked in a cupboard.
He said the clauses would not prevent anyone owning an air rifle, but would make "the reasonable precautions measurable".
"And I think it's important that for the memory of children and young people like George Atkinson that we seek to have reasonable precautions," he added.
Correction 11 January 2019: An earlier version of this article incorrectly referred to a proposed ban on military grade assault rifles and has since been amended.