Can we transfer money into a mortgage offset account and use it to buy a property and claim it as a tax deducation?

Q.

We will be moving in a few months and we want to rent out our home which is currently our principal place of residence. We have a standard variable loan with $150,000 owing and $80,000 sitting in a redraw as we made extra repayments over the last four years. As we are unable to redraw this amount to pay for new principal place of residence is there any way that we can claim our $80 000 to us for our new PPOR so that we can claim the interest on $150k plus $80k ($230k in total) as a tax deduction. Someone mentioned opening a mortgage offset account and transferring the $80k into this and then we can use this money for the new home and then claim this as a tax deduction.

Unfortunately you cannot rewrite history. Therefore the interest on the current loan of $150,000 is all that can be claimed as a tax deduction. I suggest you put this loan on an interest only basis immediately if you intend to keep the property.