Encouraged by Webster and new confidante Richard Verrall, in the mid-1970s Tyndall returned to his openly hardline approach of promoting biological racist and antisemitic ideas. This did not help the NF's electoral prospects. In the 1979 general election, the NF mounted the largest challenge of any insurgent party since the Labour Party in 1918, with 303 candidates. Among them were Tyndall's wife, mother-in-law, and father-in-law. Tyndall stood in Hackney South and Shoreditch, securing 7.6%; this was the Front's best result that election, but was down from the 9.4% they had gained in that constituency in October 1974. In the election, the NF "flopped dismally", securing only 1.3% of the total vote, down from 3.1% in October 1974. This decline may have been due to the increased anti-fascist campaigning of the previous few years, or because the Conservative Party under Margaret Thatcher had adopted an increasingly tough stance on immigration which attracted many of the votes that had previously gone to the NF. NF membership had also declined, and by 1979 had fallen to approximately 5,000. Tyndall nevertheless refused to dilute or moderate his party's policies, stating that to do so would be the "naïve chasing of moonbeams". In November 1979, Fountaine unsuccessfully tried to oust Tyndall as leader, subsequently establishing the National Front Constitutional Movement.