Bernie joined the Tottenham Labour Party in 1973, and held numerous positions within the local party before being elected a councillor in 1978. His impact was immediate, and within a year he was Deputy Leader of the Council.

By 1985 he had become the Leader of Haringey Council, the first ever-black person to hold such a position in Europe. As leader he pioneered a number of equalities policies to eradicate all forms of discrimination. During this time Haringey Council was one of the few local authorities to develop policies allowing greater access for the disabled, tackle gender and racial discrimination as well as tackling discrimination on the basis of sexual orientation.

The disturbances on Broadwater Farm Estate in 1985, brought him to national prominence, as he defended the youth against police harassment. Despite meeting the full force of the racism of the British press he refused to compromise.