In 1972 Tyndall became the NF Chairman. Under Tyndall, the NF achieved its best result in the Bromsgrove by-election, where it attracted 16 per cent of the vote.

However, former Chairman of the NF, John O'Brien, denounced Tyndall on television as a Nazi. In October 1974, John Kingsley Read replaced Tyndall as Chairman. He had once been Chairman of Blackburn Young Conservatives.

Kingsley Read and his supporters left the NF to form the National Party in1976, leaving the party chairmanship in Tyndall's hands. Anthony Reed-Herbert, another prominent member, left to form the British Democratic Party (BDP).

The mid-seventies saw a rapid rise for the NF. Membership grew to 17,000 and the party gained substantial votes in local elections.