Conservatives got a higher percentage of the vote from non manual workers than manual workers who voted more for Labour - trade unions had a greater impact on politics and Thatcher wanted to reform trade unions
A reason for class dealignment
Embourgeoisement - poorer underclass of manual workers became more affluent so their interests and party loyalties changed while still being identified as a lower class
A reason for class dealignment
Changes in the occuptional and industrial structure - manual wokers were for the first time a minority so more non manual workers made it harder to define class as the lower class was no longer just manual labourers