Final answer:
At the 1959 Blackpool Election, Gaitskell attempted to abandon Clause 4 of the British Labour Party's constitution.
Step-by-step explanation:
In the 1959 Blackpool Election, Gaitskell, leader of the British Labour Party, tried to abandon Clause 4 of the party's constitution. Clause 4 advocated for the nationalization of key industries and the redistribution of wealth. Gaitskell sought to remove it in order to shift the party towards a more moderate position and appeal to a wider base of voters.