FALKIRK, it turns out, is a small town far away of which Ed Miliband knows little.

With his eyes fixed on the far horizon while he dreams of a Labour Party with half a million members, you might think he had never heard of the place. That might even be his dearest wish.

Some of the three million trade unionists affiliated to his party are liable to do Mr Miliband's remembering for him in the weeks and months to come. In their memories, as in the memories of a public that cares even less for Labour's leader than it cares for David Cameron, the image will linger of a man spluttering mightily over, so it transpires, nothing at all. That is, as they say, official.

It is hardly the foundation from which to proclaim a revolution. It scarcely resembles an opportune moment for the reforging of the link between Labour and the unions. But since Mr Miliband is in no position to be deterred by humiliation, he has pressed on with the campaign for what he likes to call reform. Those who have just finished wondering what Falkirk was all about have a new puzzle to ponder.

It's an intricate thing. Those affiliated trade unionists gathered in Bournemouth, when they were not granting tepid applause, must have been asking themselves a serious question about the Miliband scheme. Not "Is it right or wrong?" Not, though this will come, "Is it remotely in our interests?" The primary question would have been simple: "How on earth would it work?"

So you treat three million affiliated union members like Gogol's dead souls, expired peasants still being counted fraudulently for profit and convenience. You ignore the fact that these are real people who just have to tick a box to escape the iniquity you describe. You say that none of this will do for a modern party determined to "re-engage" (or similar) with committed individuals.

So you wave goodbye to a ton of money when your party is flat broke and guess - for it is no more than a guess - that 300,000 people among the three million will be born again as committed individual Labour members. Then you invite the union leaders you have spurned to help you out by agreeing with this great one-nation project. We should perhaps rephrase the question: at which point, if any, could this possibly work?

Speaking in Bournemouth yesterday, Mr Miliband did not diverge from his scheme. It seems he is as resolute about this as he was, briefly, about the Falkirk witch-hunt. He did a better job talking about the union link than he managed when confronted by a PCS delegate with a real poser. Thus: "Can we get a clear answer: are you for or against austerity?" Those watching on TV could almost hear the breeze blowing along the Bournemouth front. The serious point remains that Mr Miliband is prepared, by his own admission, to sacrifice funding for a party with a £10m overdraft in the hope of adding members "opting in". In the process, by no coincidence, he could reduce the power of the unions in the electoral college that made him leader. If you believe in luck, he might also blunt the Tory charge that he is both Red Ed and the barons' puppet.

There is a faction within the senior ranks of Mr Miliband's party who would get shot of the unions tomorrow. They regard the link as a fetter in the pursuit of middle England's votes. But aside from the beneficent Lord Sainsbury, that group have no access to the kind of money supplied by union members. The donor-hunting of the Blair years led to that individual being interviewed by the police - something of a contrast with Falkirk - and the rich are not enthused by Mr Miliband.

Meanwhile, the Tories will not play ball over caps on individual donations, least of all for small change such as £50,000 a City skull. Why would they? Periodic scandals have become a price worth paying for a party that collected £14.6m in donations in 2012. Some of those were modest sums, of course, but since Conservative membership has fallen from 285,000 when Mr Cameron took charge to fewer than 100,000 today - "neither confirmed nor denied" - cash is not pouring in from the Tory in the street.

Either Mr Miliband truly believes he can find those 300,000 members to replace a large part of the £8m Labour received in affiliations in 2012, or he thinks the unions will block his scheme, give him a few free headlines, and cough up as usual when the 2015 election approaches. If the plan goes ahead, the new members do not materialise and he is halfway sincere about "governing for the whole country", only state funding remains.

If 300,000 people are ready and waiting to be recruited to Labour, what hinders them? If their smouldering desire for political engagement needs only to be ignited, what's the problem? The party claimed to have 193,300 members at the last count (but we'll come to that) and the great majority of those also manage to be trade unionists. No-one has put barriers in their way.

Yesterday, Mr Miliband said: "I want to make each and every affiliated trade union member a real part of their local party, making a real choice to be a part of our party so they can have a real voice in it." Some might be insulted by the claim that they have not already made a "real choice". Some, even with 90% of three million discounted, might recoil from the idea that Ed wants to "make" them do anything. But no union makes Labour Party membership impossible when dues are forked over.

Take the case of Scotland and one of the fascinating little unsolved mysteries of our political life. How many members does Labour have here? Estimates vary wildly. In Falkirk, a safe seat and a supposed bastion, the Unite union was accused of recruiting members by underhand means, thereby doubling the number from a mighty 100 to a formidable 200. If either figure is reflected across the country, and if we discount the estimated 7000 who join Labour social clubs and are tallied willy-nilly, Scottish Labour has a membership crisis.

Mr Cameron knows the feeling. The "main" political parties ceased to be mass organisations when there were only two channels on TV. There is no consuming urge today to get involved as spear carriers for organisations led by talking heads who pay only lip service to party democracy. People are these days fickle in their loyalties, as the Tories know only too well. Unions - the clue is in the word - are one of the few remaining means for harnessing large numbers of individuals with common interests.

They listen to Mr Miliband and hear that he will partly reform zero-hours contracts, that he will partly support the living wage, that he will partly tackle the housing crisis. But trade unionists yesterday also heard from a Labour leader determined no matter what to stick with inherited spending limits if he is ever elected that have crippled living standards.

And he thinks 300,000 of them will rush to support that?