Baroness Warsi is to issue a direct plea to London's ethnic communities to oppose a change in Britain's voting system by giving a speech near the site of a key protest against fascism.
The Tory Party co-chairman will give an address tomorrow at Toynbee Hall in Whitechapel, close to Cable Street which saw running battles between pro and anti-fascist demonstrators in 1936.
East Londoners took to the streets to oppose a march by Oswald Mosley's blackshirts, setting up barricades and clashing with police trying to maintain order.
Lady Warsi will argue that a switch to the alternative vote will benefit extremist parties like the BNP by allowing their supporters more say in who is elected. She will say that this will force mainstream political parties to pander to extremist voters as they seek to secure second preference votes.
She will insist that the first-past-the-post system has served generations of immigrants well.
Aides said the issue was of personal importance to Lady Warsi, a patron of "No to AV" who fought the seat of Dewsbury in the 2005 general election where the BNP secured 5,066 votes - more than the difference between the first and second-placed candidates.
Supporters of AV deny claims the system would benefit extremists.
