For a variety of spectroscopic methods, control over the polarization of attosecond pulses is necessary to probe chiral-sensitive light-matter interactions  at ultrafast time scales. This is a challenge that goes beyond generating individual harmonics of particular polarization  , since filtering individual harmonics will lose the sub-femtosecond temporal resolution. In our work, we combine a bichromatic counter-rotating circularly polarized (BiCRCP) driving field with a spatial inhomogeneity. We show that the direction and strength of the plasmonic-enhanced field provides a knob to shape the polarization of attosecond pulses from a High Harmonic Generation (HHG) process . Plasmonic-field-assisted HHG with linear polarisation yields a significant energy enhancement  , but relies on the photoelectron trajectory to be (dominantly) parallel to the polarization and inhomogeneity. HHG with BiCRCP driving fields can generate a spectrum consisting of doublets of harmonic orders with alternating helicity  , but this requires a three-fold-symmetry which is broken by the plasmonic-enhanced field.