Nick Aldworth, a former national counter-terrorism co-ordinator who will also join Ms Murray on the march, said the public was still “no safer” than at the time of the Manchester attack.
“The one thing all families who lose loved ones to terrorism want is to make sure we learn the lessons from their tragedy,” he said.
A Home Office spokesman thanked Ms Murray for her “tireless support in the development of this vital reform”.
The spokesman said that it was important to strike the right balance between public protection and “undue burdens on smaller businesses and premises”.
“We are reviewing the findings [of the public consultation] to ensure all feedback is fully considered, and working to finalise the legislation with a view to introducing it as soon as parliamentary time allows”, the spokesman added.
