LISBON, Jan 8 (Reuters) - Portugal"s ruling centre-left Socialists remain favourites to win a snap parliamentary election on Jan. 30, but the main opposition Social Democrats are narrowing the gap, according to a new opinion poll. Prime Minister Antonio Costa"s ruling party commands 38% support, according to the survey by the Catolica University published late on Friday by the newspaper Publico and the RTP state TV channel. That represents a drop of just one percentage point from an earlier poll published on Nov. 5. The centre-right Social Democrats have risen to 32% support, from 30% in Catolica"s previous survey, a trend that"s in line with another recent poll. read more Costa"s two former allies - the Communist-Greens alliance and Left Bloc - garnered 6% each, the new poll found. In October, these two left-wing parties sided with right-wing parties to reject the minority government"s budget bill, triggering the snap election. The Liberal Initiative and the far-right Chega, which currently have only one member of parliament apiece, could win 5% apiece of the vote, according to the poll. Political analysts say the Jan. 30 election alone might not solve Portugal"s political impasse as no party or workable alliance is likely to achieve a stable majority, potentially undermining the country"s ability to spur growth using European pandemic recovery funds. The Socialists won 36.3% of the vote in the 2019 election, ahead of the 28% secured by the Social Democrats. The margin of error in the Catolica University poll, which surveyed 1,238 people between Dec. 28 and Jan. 5, was 2.8%.