Comparison between the Gaia and Euclid-Gaia, hereafter E-G, astrometry. The two VPDs at the top present the Gaia DR3 (left panel) and E-G (right panel) PMs. Objects in common between the two catalogues are shown in black or red, depending on the panel. Blue points are stars with a two-parameter astrometric solution in Gaia (i.e. no PMs in the DR3) and an E-G PM estimate. The middle and bottom panels show the PM errors along α cos δ and δ as a function of G magnitude in the Gaia DR3 (black points) and E-G (red and blue points) catalogues. The increase of the E-G PM errors from I_E ≲ 18.8 is related to saturation and poorly measured objects in the VIS exposures.