But Ms Amess dismisses that, saying: “Why on earth would you not want an inquest into this?
“The point of Prevent is to track down terrorists and stop them before they carry out their attack. That is what Prevent is meant to do.
“The police had a phone call the night before, why on earth would they not go to the surgery the next day?
“There’s so many people that are at fault here, and nobody is being given any answers, because I’m not being allowed a full public, open inquest, so that we can learn from our mistakes and make sure this doesn’t happen again.”
High Court papers show that Ms Amess, an actress who lives in California, filed a personal injury claim against the Home Office and Essex Police in December.
But she told the BBC: “I can’t actually do the civil claim, because that would cost, like, hundreds of thousands of pounds that obviously I don’t have.
“So my only hope was to do this inquest, and that has been taken from me.”
Essex Police said it was aware a claim form had been filed at court, but “as these papers have not been served on our force, we are unable to comment any further upon them”.
The force added that Sir David had been a “heroic public servant” and “in the immediate aftermath of his murder, two of our heroic unarmed officers ran into the face of danger, trying desperately to save him and of course detaining his killer.
“Several other of our officers attended shortly afterwards and worked with paramedic colleagues to help save Sir David, sadly they were unable to do this.”
It added that it regularly reviewed and advised around security arrangements for the county’s MPs.
“If information or intelligence comes to light to give us cause for concern of the safety of an MP we would of course advise and guide them to keep them safe and provide a policing presence where necessary.”
The Home Office said Prevent was a vital tool in tackling terrorism.
“The attack on Sir David Amess was an awful tragedy, the safety of members of Parliament is paramount and significant work has been taken forward in response to his tragic killing,” it said.
Ms Amess also paid tribute to her father as “the most hardest-working person I’ve ever met”, describing him as someone who loved helping people and who was “full of life and enigmatic and passionate”.
She said it was now “so hard” for her to be in Southend “because it just reminds me of my father”.
“I just wish that he was here to see all of this and to see Southend as a city.”