Barring a most spectacular Mossad operation - and I wouldn't put it past them - Jeremy Corbyn will be re-elected Labour leader on Saturday. There is almost nothing Labour moderates can do about this now but accept the annihilation facing them at the next election; even then, party members may still re-elect Corbyn, or choose someone from a similar background, maybe even someone more left-wing if such a thing exists.

There is nothing that can be done because the make-up of the Labour Party has now changed. Last year former Labour councillor Michael Harris wrote a fascinating piece on how the party has effectively allowed itself to be taken over.

“ There is a new left-wing political party in Britain which, for now, is called the Labour party. It may carry the name “Labour”, the blandly fonted red logo and a set of MPs, many of whom were elected while Tony Blair was Prime Minister, but this is not the Labour party you know. For decades, the British left has fantasised about creating a new political movement – well, it’s happened and will transform British politics for a generation.

When I was selected as a Labour councillor in Lewisham in 2009, my local party had 80 (mostly quite old) members. 6 people turned up to the meeting where I was selected. Probably no more than 4 people decided I was one of the best candidates to represent 18,000 people in one of the most diverse places on earth. Hardly democracy’s finest hour. Since the time of the Iraq war, the local party had pretty much been defunct, with few active members. For many years it had no local meetings at all.

Now it has nearly 250 members, almost all of whom have joined since Labour lost the 2015 election. These new members are young, diverse and will in all likelihood vote for Jeremy Corbyn to lead the Labour party. As someone on the right of the party, it isn’t false modesty to suggest that my chances of being selected by these new members would have been pretty slim.

Labour now has 610,753 members, supporters and affiliates. A staggering 1 in 15 people who voted Labour at the last general election will be able to vote in Labour’s leadership campaign.

The decision to allow anyone willing to cough up £3 to vote for the next leader was astonishingly naive in retrospect. They seem to have forgotten a basic rule of any society, organisation or club, that the lower the conditions of entry, the lower the level of trust within, and the harder it will be to maintain the culture of the club. If any of you sense a metaphor coming here, then you may be right.

In order for a society to maintain a satisfactory level of trust there needs to be some barriers to entry, and a period of time in which newcomers can demonstrate their commitment. Open borders will inevitably lead to separate identities within, a party within a party; in Labour this has manifested in the fierce hostility shown towards party moderates. A party in which members routinely threaten each other cannot have a future.

Without borders, trust and political legitimacy both decline, and Labour can now no longer depend on the allegiance of its members anymore than the British Government can on the allegiance of some of its citizens after almost two decades of record immigration. I feel sorry for many Labour centrists, who on a personal level are in my experience the best people - nicer than we Tories - but the party has fallen victim to its own naivety. And if the Blairites are upset that their opponents have purposely introduced new members because they can depend on their votes, then welcome to our world.