An economy is very complex. To make such a declaration of fact with so little information is absurd.
Post hoc ergo propter hoc. "After this, therefore because of this." It's a fallacy for a reason.
One of you will end up here next!
If one is relying on empirical data, it is too soon to make such a call.
First, the tax increases were adopted in October: UPDATE 5-Portugal launches tax hikes, enters bond market | Reuters
Second, prior to those tax increases, revenue had missed targets: Portuguese Economy Contracts for Eighth Straight Quarter - Bloomberg.
The second point illustrates the impact that a prolonged recession has been having. Austerity (tax and spending side) creates an economic drag. Therefore, the recession could initally be amplified and extended by the austerity measures. That development would have a second-order effect on tax revenue.
The critical question afterward will be whether Portugal will emerge from the recession with stronger finances e.g., will Portugal stablize and then reduce its debt relative to GDP in the medium-term. That, ultimately, will be the measure by which Portugal's austerity program is judged.