Procedure for selecting members of the VRP and ethical criteria

I read that the Ethics Council evaluates candidates for the position of a member of the High Council of Justice (VRP) and may reject some candidates due to non-compliance with ethical and integrity criteria. I am interested: what exactly are these ethical and professional criteria that candidates must adhere to, and how transparent and fair is this selection procedure? Is it truly possible to appeal the decision of the Ethics Council if a candidate disagrees with their conclusion?