Well, if you are a permanent Australian resident then the answer is a resounding yes.
Although there is a double tax agreement between the UK and Australia, the devil as always is in the detail. The agreement states that where rental income is derived in the “other” country, which in this case would be the UK, then Australia MAY tax the income as well. No great surprise then, that the ATO have decided that an invitation to tax should never be overlooked. Therefore they do tax rental income on overseas rentals.
The good news is that you will get a credit for foreign tax paid on the rental income.
Note that different rules apply for temporary residents.