The home secretary has been asked to ban a planned march in east London by the far-right group the English Defence League (EDL) amid fears of violence.
The Metropolitan Police wants Theresa May to act in light of plans by the EDL to march in Walthamstow, Waltham Forest, on Saturday.
The Met said it had made the request "based on specific intelligence".
The Home Office said the application would be carefully considered in the usual way.
Scotland Yard wants the ban enforced under section 13 of the Public Order Act.
As well as Waltham Forest, the neighbouring boroughs of Tower Hamlets, Newham and Islington would be affected by the ban.
Ch Supt Peter Terry, the force's gold commander for the march, said: "We have made this decision based on specific intelligence and information, and our message is clear: we do not want people coming into the areas to attend these events."
The EDL said on its website that its followers would travel to Walthamstow "more determined than ever before".
It said it faced "intimidation from both the far-left and their Islamist brethren".
There were violent scenes when the EDL marched in Walthamstow last month, prompting anti-fascists to stage a counter-protest.
And in August 2011, Mrs May blocked plans by the group to march through the same four boroughs and Hackney amid police fears of violence and disorder.