[sien]

There are 100K Australians in the UK.

https://en.wikipedia.org/wiki/Australians_in_the_United_King...

There are 900K plus Australians who were born in the UK. Australians who have a British parent or grandparent and can thus get a UK passport would number in the millions.

https://www.sbs.com.au/news/almost-30-per-cent-of-the-austra...

Two of Australia's last 3 Prime Ministers did part of their University Education in the UK.

The ties between Australia and the UK are substantial. Many Australians would be keen to work with the UK for some kind of trade deal.

A CANZUK style deal wouldn't be the EU, but it might be beneficial to the countries involved.

[skissane]

> Australians who have a British parent or grandparent and can thus get a UK passport would number in the millions

Generally speaking, a British grandparent does not get you UK citizenship, only a British parent does. (There are various obscure exceptions to that generalisation, but they don't apply to the vast majority of cases.)

[sien]

True, it's not citizenship, but a British grandparent gets you the right to work in the UK which can then get you a British passport.