Owen Smith and Jeremy Corbyn clash gently at first televised hustings

The BBC Labour leadership hustings shows why Jeremy Corbyn is heading for victory

It is almost impossible to come up with a scenario in which Jeremy Corbyn does not win the Labour leadership contest.

The truth of this statement could be read on the hangdog expressions of both Owen Smith and his supporters during today's Labour leadership hustings on the BBC. At one point, one of Smith's backers stood up to tell Corbyn that he was "likely to win". Smith's pantomime shout of "noooo" was so unconvincing that even his own supporter appeared unmoved. "Yes [he is]. We've got to be practical," the man told him.

Smith's attempts to convince viewers otherwise were far from impressive. When asked about the fact that just 16% of all declared constituency Labour parties (CLPs) have nominated him, Smith replied that "many of those votes were close." I'm not even sure he was convinced by this.

This argument, that the Labour leadership contest is somehow actually very close has been pushed by Smith's campaign and his supporters repeatedly over the past week. The basis for their argument appears to rest on several flawed premises. The main one is the fact that only around half of CLPs declared their nominations this time. The implication is that the other half are all secretly in the tank for Smith. Yet where is the evidence for this? Some have suggested that Smith supporters are all too intimidated by Corbynites to turn up to nomination meetings. Even if this is true in some instances, it's hardly evidence for majority support for Smith. Others have pointed to Smith's endorsement by the GMB union. They argue that if all of GMB's members turn out to back him then the race could easily be swung. There are only two problems with these arguments: turnout among union members at the last leadership election was very low and most other major unions have backed Corbyn.

In the absence of any actual evidence of a Smith surge, some of his other supporters have resorted to intuition. Writing for LabourList, Smith supporter Luke Akehurst writes that "intuitive common sense" means Corbyn can't be heading for a landslide.

Akehurst points to the fact that just four per cent of Labour members bothered to take part in CLP nominations. This is true, but it's a bit like the arguments made by some Corbyn supporters that because pollsters only survey 1000-2000 people for each poll, then somehow they're all lies and Corbyn must be heading for a general election landslide. Just because available data is imperfect, doesn't make it better than having no data at all.

Of course CLP nominations, like polls, are not an entirely perfect sample of opinion, but that doesn't mean they're worthless either. In every Labour leadership election since 1992, CLP nominations have indicated which candidate will win. Perhaps it will be entirely different this time. Perhaps when the next poll of Labour members comes out it will show that Smith is storming to victory. Of course it's possible, but again where is the evidence?

There was little evidence to support Smith's theory in today's hustings either. Throughout the debate he seemed subdued and lacking any obvious passion. On almost all the major issues, with the exception of nuclear weapons, he said he agreed with his party leader. 'Vote for me. I'm just like Corbyn except I like nukes' does not seem to me to be an obviously winning strategy.

At one point the two candidates were asked whether they would hold negotiations with Isis. Corbyn wobbled and said that he would like "proximity talks" before adding that he would not have them "round the table".  Smith on the other hand said that he would. At the time of writing, the comments are causing a major outrage with even the Conservative Party making a rare intervention into Labour's internal debate. As with his previous comments over "smashing Theresa May back on her heels" it is very hard to make the argument that you are the "competent" candidate, when you are continuously getting yourself mired in gaffes and controversies.

It was not that Corbyn had a brilliant performance today. His answers were littered with platitudes and he seemed at times to be living in an alternate reality. Asked repeatedly about which of his parliamentary critics he had reached out to, he replied that he had worked with John McDonnell. If this is what Corbyn describes as "reaching out" to critics, then there seems little hope of the party coming together after this race. His response to questions about the abuse of Labour MPs by his supporters were unconvincing. Corbyn was also visibly irritable at times. Interrupted by Smith at one point, Corbyn's voice rose to a rather comical falsetto as he told his rival to "let him him finish".

Did Corbyn supporters notice any of this? It's not clear.

However, before the debate started, the BBC divided their audience of Labour members and supporters into three groups: Corbyn supporters, Smith supporters, and the undecided. At the end, the host Victoria Derbyshire asked those in the latter group to move over to the group of the candidate who had most convinced them. The overwhelming majority moved over to Corbyn's camp.

The caricature of Corbyn supporters as all being blind untouchable loyalists living in their own bubble is somewhat unfair. Yes many of his supporters are oblivious to the electoral realities that suggest Labour are heading for a crushing defeat under Corbyn. Yes many of them are convinced that because everybody they follow on Facebook and Twitter supports the Labour leader, then he must somehow be heading for Downing Street. But as previous polling of Labour members has shown, many of those who do support him also have big doubts about his leadership and chances of becoming prime minister.

Had a credible and obviously superior alternative leader put themselves forward in this election, many of those people may have been convinced to switch their support over to a new alternative.

Instead Labour members are left with a choice between two leaders, neither of whom seem likely to win the next general election, but at least one of which seems like the real deal. Faced with a choice between an authentic but flawed incumbent and a little known, but questionable imitation, the majority of Labour members will almost certainly opt for the former.