Police and troops were heckled by a Jeremy Corbyn supporter while in their posts outside the gates of Downing Street.
The unidentified woman, wearing a backpack emblazoned with a picture of the Labour leader and the word ‘Hope’, told security officers she was objecting to ‘the vile woman who is going to get you killed’.
In a video taken by LBC political editor Theo Usherwood, the woman can be heard saying she is ‘the voice of the people’ and asking officers and military personnel to ‘walk with her’ as police try to calm her down.
After moving away from the gates, she stood in the middle of Whitehall and shouted: “Get rid of the warmongers who want the war to continue.”
The military were drafted in to assist armed police in guarding key landmarks across London on Wednesday, including the Palace of Westminster, which is closed to visitors until further notice in the wake of the Manchester attack and the terrorism threat level being upgraded to critical.
The woman was directed away from Downing Street by police and is not thought to have been arrested.
Labour has confirmed it will resume national election campaigning on Friday.