The embattled shadow home secretary was taken to task by Sky News presenter Dermot Murnaghan during an embarrassing interview.
In a grilling, the presenter asked her about the Harris Report, commissioned by Sadiq Khan in 2016.
The report outlined 127 recommendations on how best to deal with terrorism.
It has come back to the fore following the devastating attack in London Bridge at the weekend when three jihadis rammed a van into innocent pedestrians leaving seven dead and 48 injured – including 21 critically.
Diane Abbott faced a battering on Sky News from Dermot Murnaghan
But in another embarrassing interview, Mrs Abbott seemed unaware of the report.
It was an alarming prospect as she could be home secretary in just four days.
During the interview in which she stumbled over her words, Mrs Abbott said: “I know he was talking about preparedness and resilience. I think we should act on it, not necessarily all of the recommendations."
In another embarrassing interview, Mrs Abbott seemed unaware of a report
But when she was asked to comment on the specifics, she appeared not to have even read the report.
Mr Murnaghan pressed: "What do you think about the recommendations about various police forces? That they should work closer together?"
The presenter replied: "No that they should amalgamate. Have you actually read it?"
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Ms Abbott said that she had read the report but appeared unsure on what was in it.
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Mr Murnaghan pressed: ”What about physical resilience?"
She responded: "Well I think physical resilience is important."
"Well I think physical resilience is important," she repeated.
Mr Murnaghan continued: "Well what about barriers, mentioned in wake of Nice attacks?
She replied: "Well we are now putting up barriers on, erm, bridges. We are putting them up."
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Outspoken Shadow Home Secretary, Diane Abbott holds strong opinions which does not always go down well.
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Abortion is an issue of conscience for the Labour party.
This is the latest in a series of terrible interviews for the Labour MP in which she appeared shaky on the facts that she should know in her role as home secretary.
She also faced a grilling at the hands of Channel 4 News' Jon Snow over the reaction to the terror attacks.
The journalist said: “Diane Abbott, let’s just be quite clear about this. You and Jeremy Corbyn appear to have been on a journey, you started out on this campaign more or less anti-Trident – although tolerating its continued development – and you’ve now passed through an extraordinary pain barrier which has you backing shoot-to-kill and, indeed, calling for more armed police!
“This is not the old Labour shadow home secretary we knew of old…”
Ms Abbott, who had previously been criticised for not offering interviews in the wake of the attack, claimed it had always been Labour Party policy to allow the police to use “maximum force where peoples’ lives are threatened”.
The shadow home secretary said: “I am here on the fields of City Hall, having just attended vigil. It was a very moving occasion and I think the people of this country and the people of London want to give their support and sympathy to the injured and sadly to the tragic victims.
“On the question of my position, or the Labour Party’s, on shoot-to-kill, it has always been the position that we believe the police can use maximum force where peoples’ lives are threatened.
“There is no question on Saturday night in Borough Market that peoples’ lives were threatened – of course, you had to use maximum force.”
Seven people were killed and 48 more injured when three terrorists launched an attack on innocent people on London Bridge and Borough Market on Saturday night.