Based on the success of the X-band Transverse Deflecting Structure (TDS) diagnostic at LCLS, a collaboration between DESY, PSI and CERN has formed with the aim of developing and building an advanced modular X-band TDS system. The designed TDS has the new feature of providing variable polarization of the deflecting field. The possibility of changing the orientation of the streaking field of the TDS to an arbitrary azimuthal angle allows for 3D characterization of the phase space using tomographic methods. Moreover the complete 6D characterization of the beam phase space is possible by combining this technique with quadrupole scans and a dipole spectrometer. As this new cavity design requires very high manufacturing precision to guarantee highest azimuthal symmetry of the structure to avoid the deterioration of the polarization of the streaking field, the high precision tuning-free assembly procedures developed at PSI for the SwissFEL C-band accelerating structures will be used for the manufacturing process. The high-power rf system is based on the hardware developed for the CERN X-band test stands. We summarize in this work the status of the project and its main technical parameters.