So why is that very unlikely?

The Herald reports:

But the Prime Minister said like many “big personalities” who have tried in the past, it wasn’t easy to get into Parliament.

“There are plenty of people who have come into politics with quite a bit of cash and a big personality and haven’t really got there,” he said.

“I think it is very unlikely that he’d get above 5 per cent, but I mean if and the Greens really implode he could.

Not sure Labour imploding is very unlikely. If the best they can come up with after two years of studying the future of work is a new tax on employers, their propensity for self-immolation should not be under-estimated.