  Plasmonic metasurfaces enable simultaneous control of the phase, momentum,
amplitude and polarisation of light and hence promise great utility in
realisation of compact photonic devices. In this paper, we demonstrate a novel
chip-scale device suitable for simultaneous polarisation and spectral
measurements through use of six integrated plasmonic metasurfaces (IPMs), which
diffract light with a given polarisation state and spectral component into
well-defined spatial domains. Full calibration and characterisation of our
device is presented, whereby good spectral resolution and polarisation accuracy
over a wavelength range of 500-700~nm is shown. Functionality of our device in
a M\"uller matrix modality is demonstrated through determination of the
polarisation properties of a commercially available variable waveplate. Our
proposed IPM is robust, compact and can be fabricated with a single
photolithography step, promising many applications in polarisation imaging,
quantum communication and quantitative sensing.
