In 1968, Chesterton's leadership was challenged by ex-BNP member Andrew Fountaine. A leadership election produced a strong mandate for Chesterton, and his challengers left the party. Throughout this, Tyndall remained loyal to Chesterton. There were further arguments in the party after the lease ended on its Westminster headquarters. Ex-LEL members wanted another base in Central London, while the ex-GBM and ex-BNP factions favoured moving into the GBM's old headquarters, the "Nationalist Centre" in Tulse Hill. Chesterton backed the ex-LEL position, and rented a small office in Fleet Street. In April 1968, immigration became the foremost political topic in the national media after the Conservative Party politician Enoch Powell made his Rivers of Blood speech, an appeal against non-white immigration into Britain. Although Powell proposed more moderate policies for expelling migrants than the NF, his use of language was similar to theirs, and a growing number of individuals on the right wing of the Conservatives defected to the NF.