Venues 'still too vulnerable to attacks'
A former National Counter Terrorism Co-ordinator has told the BBC the government is not doing enough to ensure that venues are secure.
Nick Aldworth has warned new legislation is needed to reduce the impact of any future attack.
He is supporting a campaign for more rigorous checks at venues, under the name Martyn's Law, after Martyn Hett, a victim of the Manchester Arena attack.
He said such a law could have prevented the spate of attacks in the UK in 2017.
At the time, Mr Aldworth was a Metropolitan Police chief superintendent in charge of keeping Londoners safe.
"People died on my watch when I was responsible for trying to keep London and, more subsequently, the UK secure," he said.
"That's a burden that I will carry."
He said new legislation would help to stop that happening in the future.
"I think without it we have the potential for places to be attacked and for the potential for the effect of those attacks to be far worse than they need to be."
'Reckless and negligent'
At the moment, venues such as theatres, cinemas, and concert halls do not have any legal obligation to put counter terrorism security in place, or to plan for what they would do in the event of an attack.
"I think that without being specific - because there are coroners' inquests under way at the moment - I think there are definitely some places that could have benefitted from some infrastructure," Mr Aldworth continued.
"But one of the things I was told after one of the attacks by a survivor... was she was in a restaurant and nobody knew what to do."
Many places do have bag checks and security screening but Mr Aldworth said it was not the case everywhere, and that some venues were "reckless and negligent".
Martyn Hett's mother Figen Murray started a petition last year demanding more security at venues and has attracted more than 23,000 signatures.
She wants it to be compulsory for every venue to assess the risk of an attack, and put appropriate measures in place.
Mrs Murray does not suggest there should be a security arch in front of every door, or that the country should become "Barrier Britain".
"When I think of people like Martyn who enjoyed music festivals and all these events without having to go through lots and lots of security, we're talking about common sense here," she said.
"It could just be people trained in recognising suspicious behaviour - it can be even as basic as that."
Mrs Murray already has the support of some venues that say they do not see extra legislation as a problem.
Shaun Hinds, chief executive of the Manchester Central Convention Centre, said: "I'd actually flip it on its head and look at it as a business opportunity and say, 'Well, actually if we can demonstrate that we're putting the appropriate measures in place to ensure the security of the visitors, the venue, the employees, then actually that's got to be a good thing'."
'Enjoyed without fear'
Responding to the calls for Martyn's Law, security minister Ben Wallace said: "Going to concerts, exhibitions, shopping centres, watching sport and other events are part of the fabric of life, things that should be enjoyed without fear.
"Just as we share enjoyment of these communal places and spaces, we need to share concern and responsibility for keeping them as safe as possible.
"That means owners, operators and public authorities stepping up and making full use of the wide range of information and advice available to support them.
"Government is also considering whether and how further legislation could support, or indeed compel, effective and proportionate protective security.
"We would very much welcome input from Figen Murray and others campaigning for Martyn's Law in this work and I look forward to discussing it with her soon."
At an event to launch the Martyn's Law campaign, Greater Manchester mayor Andy Burnham said: "Security against terror attacks at venues should be mandatory not discretionary."
Mr Burnham said Manchester was ready to be the first city to endorse the new legislation and become a pilot area.
At the event, attended by Mrs Murray and Mr Aldworth, he said venues were ready to sign up to the measures required.
All five Tory leadership candidates have tweeted their support for Martyn's Law and a requirement for improved security measures at public venues.