Leaders of the English Defence League have lost a High Court fight for the right to demonstrate in an area which they say is "subject to Sharia law".
They objected to police preventing a English Defence League (EDL) march - planned for Saturday - entering Tower Hamlets in east London.
Police said they had imposed restrictions on marchers because they feared an outbreak of "serious public disorder".
Judge Mr Justice King ruled that the police decision was reasonable and proportionate, following a High Court hearing in London.
He blocked a EDL attempt to pursue a judicial review.