A four gap MWPC is undergoing an ageing test at the CERN Gamma Irradiation Facility (GIF). The first results of this study are based on the analysis of the chamber behaviour after accumulation of a linear charge density of about 0.25 C/cm, corresponding to approximately 5 years of operation in LHCb under the worst conditions expected for this chamber type. No any deterioration is observed to prohibit the use of these chambers in LHCb experiment.