In this work natural convection within a two‐dimensional fluid saturated Darcy porous layer is considered. The porous material is in a large aspect ratio rectangle with its sides inclined with respect to the gravity vector. All four faces are exposed to uniform heat fluxes, opposite faces being heated and cooled, respectively. Analytical solutions for the streamfunction and temperature fields in the central region are deduced using a parallel flow assumption. Numerical confirmation of the analytical results is also obtained. For high enough Rayleigh numbers multiple steady states around the rest state are found. These states represent unsymmetrical flows in opposite directions. The critical Rayleigh number for the onset of motion determined from a stability analysis corresponds to that for the existence of unicellular convection using the parallel flow approximation. Linear stability limits of each of the multiple states are also calculated. One of the convective flows is found to be stable to higher Rayleigh numbers than the other.