Quote [ The relationship was lost following the winter of discontent ? It was the relationship which became too one sided ,union side, that caused the voter to turn away from the party 1979 to 1997] End Quote.
It is undeniable that the Trade Unions reacted entirely with the wrong policy to the downturn in the economy in the mid 1970s leading to the "winter of Discontent". The foregoing gave rise to a decline in the relationship between the Unions and the Labour Party, which undoubtedly had profound major implications for both organisations in the above quoted years.
The above divisions were cleverly exploited by Maggie Thatcher, who, (while the Labour Party was in a policy wilderness and the Trade Unions in decline) brought forward what many now believe to be the most discriminatory social and industrial policies ever witnessed in the United Kingdom. Those policies are still having an effect on Britain even today, which can be seen in housing, wages and social mobility.
Those circumstances have brought forward Trade Union community branches, Momentum and a growing left wing Labour party with policies that younger "middle Britain" people can associate with.
The foregoing "middle Britain" younger generation would have voted conservative in the mid 1980s to mid 1990s, but by 1997 the fault lines in the Thatcher's policies were beginning to show, hence the election of Tony Blair in that year. However the Blair Labour government was gradually seen by many as just a milder version of Thatcher's policies which would not redress the growing inequalities those policies had brought about.
The Labour Party of today is a reflection of more than four decades of establishment thinking and rule, and in that is found the huge rise in its membership and left wing Leadership. For to be a Conservative you have to have something to conserve. Many in middle Britain cannot even get on the housing ladder or obtain a wage or salary to maintain their families to what they believe is an acceptable standard.
The above are the reasons why Momentum and Jeremy Corbyn have obtained the positions they have