From the Labour conference

Ed Miliband has become the latest leading Labour figure to come out in support of open primaries for Westminster constituencies. At a fringe meeting this evening, I asked the Climate Change Secretary whether he backed the proposal, which would allow non-party members to select parliamentary candidates.

Miliband replied that while he had some anxieties about the idea, he now believed the "tide of history" was with primaries.

He said: "If you put a gun to my head and asked where I'd land I'd say with open primaries."

Others who have backed open primaries include James Purnell, David Miliband and Tessa Jowell. Until now the idea has largely been seen as one favoured by the "Blairite" wing of the party but Miliband's response proves it's gaining ground on the centre left, too.

At a time when all the major parties are haemorrhaging members, I'm sceptical of anything that further dilutes the status of those who remain. It's very hard to point to any direct influence, aside from selecting election candidates, that members enjoy. The introduction of primaries would provide another excuse for thousands of people to leave the Labour Party.

I'm also concerned that primaries would lead to a big increase in the influence of money on election contests. Candidates competing to win the support of thousands of voters would be required to spend substantially more on their campaigns.

The influence of money on US congressional primaries is well evidenced by the fact that 40 of the country's 100 senators are millionaires. A cap on spending could remedy this problem but it's another question mark over an idea that doesn't deserve the status it's acquired.