The family of PC Keith Palmer, who was killed by a man pledging allegiance to Islamic State, say they have been let down by Scotland Yard and “come below” terrorist Khalid Masood.

Masood attacked PC Palmer outside the gates of the Palace of Westminster in March 2017 with two large knives as he stood guard protecting the site.

The radical converted to Islam in prison and had been known to security services since 2004 after his phone number was found on a terrorist’s phone.

The heroic officer’s sisters, Angela Clark and Michelle Palmer, say that the force is now blocking their fight for justice and passing on blame.

They told The Times their queries about weakness in Parliament’s security had been ignored and they felt “battered” and “not valued”.

London’s Metropolitan force has become hostile during the inquests, they say, after initially promising relatives they were members of a policing family after PC Palmer’s high-profile funeral.

Speaking on behalf of their mother, 71, they said they are worried that the force is “scapegoating” more junior officers over the alleged security failures during the Islamist attack.

Michelle, 46, told the newspaper: “Keith gave his life and we’re left with no answers. Eighteen months on we were hoping for some closure, but were not going to have that.

“We feel like we come below Khalid Masood. We are not valued, not wanted, we feel like we are on trial. We are not valued, not wanted. We feel like we are being battered.”

Angela, 52, added: “We put our faith in this system, that we would get answers. And we’re now utterly demoralised, our faith is gone.”

The inquest into the Westminster bridge attack opened last month. Dozens were injured and five killed by 52-year-old Masood, who used a rented van and knives as his chosen weapons.

PC Palmer was unarmed when the attack happened and his sisters, both from southeast London, are trying to establish whether the presence of armed officers would have saved his life.

Firearm officers have been stationed behind the closed gates in a fixed position since the attack took place. Mrs Clark said they were worried that the officers would be used as a “scapegoat”.

She said: “They were just doing their job, like Keith was. There are certain people at command level who are perhaps finding it easier to blame the people that were on the ground.”

The Met said they had not been able to respond to the family’s questions “because many of the requests were ill-founded and/or were not processed further by the inquests team”.