  In this work fluctuations in the electric field of surface plasmon polaritons
undergoing random scattering on a rough metallic surface are considered. A
rigorous closed form analytic expression is derived describing second order
correlations in the resulting plasmon speckle pattern assuming statistically
stationary and isotropic roughness. Partially coherent planar Schell-model
source fields can also be described within the developed framework. Behaviour
of the three-dimensional degree of cross polarisation and spectral degree of
coherence is also discussed. Expressions derived take full account of
dissipation in the metal with non-universal behaviour exhibited within the
correlation length of the surface and source fields.
