Japanese Prime Minister Shinzo Abe’s ruling coalition won a comfortable majority in the upper house of parliament in elections on Sunday, giving it control of both chambers and a mandate to press ahead with difficult economic reforms.

The win is an endorsement of the Liberal Democratic Party’s “Abenomics” programme, which has helped spark a tentative economic recovery in Japan. It’s also a vindication for Mr. Abe, who lost upper house elections in 2007 during his previous stint as Prime Minister.

“We’ve won the public’s support for decisive and stable politics so that we can pursue our economic policies, and we will make sure to live up to the expectations,” Mr. Abe told public broadcaster NHK after he was projected to win based on exit polls and early results. Official results weren’t expected until early Monday.

The victory also offers the hawkish Mr. Abe more leeway to advance his conservative policy goals, including revising the country’s pacifist constitution and bolstering Japan’s military, which could further strain ties with key neighbors China and South Korea, who are embroiled in territorial disputes with Japan.

Controlling both houses of parliament has been an elusive goal for Japanese governments in recent years. With a divided parliament, it has been hard to pass legislation, and voters fed up with the gridlock and high leadership turnover appeared willing to opt for the perceived safety of the LDP, which has ruled Japan for most of the post-World War II era.

Mr. Abe said voters supported the LDP to press ahead on his party’s economic policies, and said it would be the government’s top priority.

“Now that we got rid of the twisted parliament, the LDP is going to face a test of whether we can push forward the economic policies so that the people can really feel the effect on their lives,” Mr. Abe told NHK.

Japan’s stagnant economy is showing signs of perking up, helped by the aggressive monetary and fiscal stimuli that Mr. Abe has implemented since he took office in late December. Stocks have surged, business confidence is improving and the weaker yen has put less pressure on vital exporters.

“I want them to carry on doing their best as the economy seems to be picking up,” Naohisa Hayashi, a 35-year-old man who runs his own business, said after casting his ballot at a downtown Tokyo polling station.

But long-term growth will depend on sweeping changes to boost competitiveness and help cope with Japan’s rapidly graying population and soaring national debt. Such reforms, long overdue, are bound to prove difficult even with control of both chambers of parliament.

Mr. Abe also faces a decision this fall on whether to follow through on raising the sales tax next April from 5 per cent to 8 per cent, a move needed to shore up Japan’s public finances, but one that many worry will derail the recovery.

Based on exit polls and early results, NHK predicted that the LDP and its coalition partner, New Komeito, won a combined 74 seats, giving them a total of 133 seats in the upper house, more than the 122 needed for a majority.

The LDP was projected to have won 64 seats, which together with the 50 it held before the elections would give it 114, short of an outright majority.

The main opposition Democratic Party of Japan, which fell from power in December elections, was projected to lose nearly 30 seats.

Voter turnout was low, suggesting a lack of public enthusiasm. According to Kyodo News agency, 52 per cent of eligible voters cast ballots, the third-lowest turnout since the end of World War II.

More In: World | International | News