Abstract Temperature dependence of work function change 〈Δϑ〉 caused by adsorption of Cu on W(110) at very low coverages is examined. The phenomenon reported by Kołaczkiewicz and Bauer is explained by mutual depolarisation of nearest neighbours during formation of two-dimensional islands in the adlayer. It is assumed that Cu adatoms are polarisable and neutral. The work function change is taken to be equal to dipole potential barrier produced by the induced dipole moments of adatoms. Changes in arrangement of adatoms accompanying the formation of the islands are modelled by Monte Carlo simulations, using the continuous space model of submonolayer with a realistic intermodular potential given by Gollisch.