Brendan Cox, the widower of murdered Labour MP Jo Cox has co-founded a new group to lobby the Government on counter-terror policies and improved support for victims.
The Survivors Against Terror group is being founded by survivors and bereaved relatives of victims of Islamist bombings, IRA attacks and far-right extremist murders.
The group aims to campaign for more effective policies to combat terror and identify gaps in support for victims and the bereaved, as well as help the public tackle hate speech and the terror threat.
Other founders of the organisation includes; Dan Hett and Figen Murray, the brother and mother of Manchester bombing victim Martyn Hett, Paralympian and 7/7 survivor Martine Wiltshire, Mike Haines, whose brother David was beheaded on camera after being held captive by Islamic State in Syria, and Tunisia resort shooting victim Gina Van Dort.
They said: "Our collective view is that terrorism can be defeated - but only if we pull together as a country to fight it more effectively. "We will work to build a voice for survivors."
The founders said: "As a group of survivors and family members we have had mixed experiences of support from the government and other service providers.
"In some cases this has been exemplary, in other cases families and survivors have been left with no support at all.
"We will be reaching out to other survivors and bereaved families to build a better picture of what is and isn't working and will be talking to the government and other service providers about the gaps we identify."
The new group also called on social media companies to take stronger action and urged traditional media to treat survivors more respectfully.
Home Secretary, Amber Rudd, welcomed the creation of the new group.
She said: "I have incredible admiration for the courage and dedication of everyone involved.
"Their ambition to bring positive change as a response to their horrific experiences is truly inspiring.
"We are committed to providing the best support for victims of terrorism, and that is why last year we set up the Victims of Terrorism Unit which will make sure that support, both in the UK and overseas, is comprehensive and made swiftly available to those who need it.
"I look forward to working with Survivors Against Terror to ensure that their experiences help shape the work we do."
Mother-of-two Jo Cox - the Labour MP for Batley and Spen was shot and stabbed to death on 16 June 2016 in the street by far-right terrorist Thomas Mair.
Mair was jailed for life for the murder of the 41-year-old.