Tier 1 visa - new born baby - immediate travel outside UK

Good morning all!

Got an issue that I cannot seem to find an answer on. Hopefully someone might be able to help.

My wife and I are currently living in the UK on Tier 1 Visas.
We are expecting a baby in mid August.
We then need to duck off back to Australia for a wedding in early October (with the baby) - and then return to the UK (say after about two weeks in Australia)

Now, there is not too much time between mid August and early Oct.
We obviously need to pick up an Australian passport during this time.

But the key question is, what happens with the baby's immigration status when we arrive back in to London in late October?
Should we be trying our best to get a personal appointment with the UKBA to get a tier one visa (after we get a passport, but before we depart)? Or, given the tight timelines, is there some concession that means we can bring the newborn back into the UK without any special UK visa?

Not sure what to do.

Any help appreciated.

This is what happened to my friend who was on Tier 1 visa.

He and his wife went to india for holiday with their 1 year old child. Child was born here and didn't had dependant visa. The whole family had indian passports, incl. kid.

When they were returning back from India, the kid was not allowed to travel as he didn't had visa. They have to leave the kid back with their parents. After that he went back, applied for his dependant visa from India, and brought him here.

So, my suggestion is do not travel out of UK without getting the dependant visa for your kid.

Need to talk at HCI for arranging urgent passport, and apply for PEO teir-1 dependent visa.