Pro Se in Tax Court?
Ditto!
Yes; of course you can represent yourself; in fact, everyone can self represent in any type of case and in any court of law.
But you may want to hold on to your attorney for guidance until after depositions are taken and interrogatories are completed and returned before going pro per, and I would be remiss if I did not suggest that you reconsider going solo in tax court. Because quite frankly, and no pun intended here, I would feel a lot more inclined to represent myself in a murder case than in a tax audit case and you need only do a side-by-side volume comparison of the Penal Code and the Tax Code to see why.
And as has been mentioned here already, apart from the Tax Code, there is also the small matter of familiarity with Civil Procedure to know when to hold and when to fold.
fredrikklaw