Andrew Holness (R), leader of the opposition Jamaican Labour Party, speaks to supporters at the party headquarters after they won the general election in Kingston, Jamaica February 25, 2016. REUTERS/Gilbert Bellamy

KINGSTON (Reuters) - A final vote count showed Jamaica’s opposition won last week’s general election with a one seat margin, electoral authorities said on Tuesday, ending days of uncertainty over the outcome of the close race fought in the shadow of a tough austerity plan.

The electoral commission said the Jamaican Labour Party won 32 of 63 seats, just enough to end Prime Minister Portia Simpson-Miller’s bid for a second term and clearing the way for JLP leader Andrew Holness to be sworn in as the heavily indebted nation’s next prime minister, as soon as Thursday.

The JLP won on promises of tax cuts and job creation, but is set to take the reins of a nation saddled with a debt to GDP ratio of around 125 percent, high unemployment and a sluggish economy.

The ruling People’s National Party (PNP), which lost some seats by just a handful of votes, had been credited with improving the island’s economic prospects under a strict IMF approved austerity program that included severe spending cuts.

Critics have argued that the JLP’s promised tax cuts will not be possible under its IMF obligations, but the party said on Monday that is will respect the program.

The top three global ratings agencies, all of which have upgraded Jamaica’s sovereign debt in recent months in recognition of its adherence to stringent fiscal targets, also predicted the JLP would not deviate much from the agreement with the IMF.

“There is a pretty broad consensus around the need to reduce government debt, and the IMF program is an anchor for that,” said Charles Seville, Senior Director at Fitch Ratings, North America Sovereign Ratings.

S&P and Moody’s expressed similar sentiments.