Incumbent Swedish Prime Minister Fredrik Reinfeldt is heading for a comfortable victory in next weekend's election, according to an opinion poll released Sunday. With a week to go before next Sunday's contest, a centre-right coalition of four parties under Reinfeldt's Moderate Party led the likely Social Democrat, Green and Left parties' coalition by 51.7 per cent to 42 per cent, dpa reported. The Social Democrat party, under Mona Sahlin, itself only scored 28.7 per cent, the poll for the Svenska Dagbladet newspaper found - lower than its result in the last election in 2006. That would be a major setback for the party that led Sweden for most of the 20th century. Of particular interest in next Sunday's election will be the support for the far-right nationalist Sweden Democrats, who will be looking to clear the 4-per-cent hurdle to enter parliament. If they do take seats, it could deprive Reinfeldt's coalition of an outright majority. Tax relief has been a major campaign issue in the highly prosperous Scandinavian nation of 9.5 million people.