Mum of Manchester Arena victim Martyn Hett relieved as bill enters Commons

The meeting came after Ms Murray walked 200-miles from the site of her 29-year-old son’s death, alongside 21 other people at the Ariane Grande concert at Manchester Arena in 2017, all the way to London to campaign for Martyn’s Law.

Under the draft legislation, all venues with a capacity of more than 200 people would be legally required to have plan to deal with an attack at their premises.

Other requirements at this level include training staff on “simple and low cost” procedures like identifying safe exit routes and locking doors and windows.

Venues with a capacity of more than 800 people will be subject to greater requirements, including measures like CCTV or security staff.

Brendan Cox, husband of murdered MP Jo Cox, and co-founder of Survivors Against Terror, said the introduction of the bill was a “major breakthrough”.

“It will finally close the security loopholes that put us all at risk,” he said.

“Survivors of terror attacks aren’t looking for sympathy – they are looking for change that makes it less likely that others will endure what they have.”