Coexistence of magnetic ordering and ferroelectricity in multiferroic materials, especially at high temperatures, is of great technological and fundamental interest. There are very few examples exhibiting this phenomenon above 200K and one of them is a charge-ordered compound LuFe2O4. We propose to use the high resolution long-wavelength diffractometer WISH to undertake a detailed study of the magnetic structure and magnetic correlations in a high quality single crystal of this multiferroic under magnetic fields and their relationship to the charge ordering.