The Labour Party has proposed that any future contested leadership elections no longer be decided solely by their Members of Parliament, but by an electoral college consisting of MPs, members and unions.
The initiative to give members a say in future leadership elections is a good thing, in my opinion. Both the UK Conservative Party and the UK Labour Party do so, as do the Canadian political parties. Most readers will also be familiar with the months of primaries in the United States, where party members vote to select their effective party leaders (their presidential candidates).
Political parties without active members lose touch with the community, and struggle to attract votes and funds. Some parties treat members as adjuncts to the all-knowing all-powerful leader (think Jim Anderton, Graham Capill, Winston Peters), but good political parties treat members as their best resource.
The challenge for political parties is to recruit and retain members. In the 1970s membership of a political party was widespread. Today, only one political party has a membership of over 15,000. Many organisations provide benefits for people who join them. Political parties tend to be the opposite - they take your time and your money and give no personal benefits. So people who tend to join are motivated to do so because they believe in the values and policies of the party.
In our political system, party leaders are very powerful. They become Prime Minister if they win the election. They have more influence over policy for a party than any other person. With a very strong leader, they can unilaterally determine policy. They get to rank their colleagues, assign portfolios and set the general direction and strategy of the party.