TOKYO ― Japan’s Prime Minister Shinzo Abe faces strong resistance to a promised economic and political overhaul despite a weekend election victory that gives him up to four more years in power.

In Sunday’s snap election, the conservative Liberal Democrats who have ruled for most of the post-World War II era locked up a solid majority of at least 291 seats. About 35 seats were claimed by the LDP’s coalition partner, the Buddhist-backed Komei party, giving the ruling bloc more than two-thirds of the 475-seat House of Representatives.

That majority will enable the coalition to override resistance in the upper house, but not necessarily the powerful vested interests and bureaucrats opposed to major reforms many economists say are needed to revitalize Japan’s economy. 

Businesses are reluctant to sink their cash hoards in a shrinking home market, farmers are dead set on keeping their cushion of subsidies and tariffs, and voters remain leery of many of Abe’s plans. The election victory changes none of that.

Japan could gain significantly by boosting its productivity through labor reforms and improving business conditions for foreign companies, but such initiatives have made little headway.

“Nor has there been any progress in the government’s stated aim of deregulation,’’ Marcel Thieliant of Capital Economics said in a commentary Monday. “Unfortunately, we fear that reform progress will remain glacial in coming years.’’

The solid majority for the ruling coalition does reduce the likelihood of challenges against Abe from within the Liberal Democratic Party. That could allow him to put off the next election until as late as December 2018.

After his win Sunday, Abe said his top priority was the economy, which fell back into recession after a tax hike in April. “Economy first,’’ he told national broadcaster NHK, adding that he would also tackle other major issues, including national security.

The “Abenomics’’ blend of aggressive monetary easing, public spending and economic reforms has pushed share prices higher and weakened the value of the Japanese yen, helping big exporters like Toyota Motor Corp. But wages and business investment have remained sluggish, and inflation and growth have fallen short of the targets set by Abe when he took office two years ago.

A quarterly survey of business sentiment released Monday by the Bank of Japan showed a slight deterioration in the outlook for coming months. Conducted after Abe delayed a sales tax hike that had been planned for next year but before Sunday’s election, it showed businesses anticipate slack demand and rising costs.

“Abenomics is still halfway through, and I feel a strong sense of responsibility to push it further,’’ said Finance Minister Taro Aso, who retained his seat in parliament.

Abe’s agenda includes labor market reforms and securing a trans-Pacific trade agreement that is strongly opposed by the powerful farm and medical lobbies.

He successfully wagered that voters would stick with him despite the recession and qualms among many in Japan over Abe’s broader agenda, which includes restarting nuclear plants idled after the March 2011 Fukushima disaster and expanding the country’s military role.

The Liberal Democrats held 295 seats before the election, and fell short of forecasts that they could win as many as 320 seats.

The main opposition party, the Democratic Party of Japan, won 73 seats ― a stronger showing than many had expected. But the party’s leader, Banri Kaeda, lost his seat and the party remains weak and in disarray after it lost power in 2012.

The Japan Communist Party, a traditional protest vote option, nearly tripled its seats to 21, while another opposition party, the Innovation Party, took 41 seats.

“I believe the results show that we have received a public mandate for the Abe administration’s achievement over the past two years,’’ Abe said in a live television interview with Tokyo Broadcasting System. “But we should not be complacent about the results.’’

In Washington, the White House congratulated Abe on his election victory, calling the U.S.-Japan alliance “the cornerstone of peace and prosperity in the Asia-Pacific.’’ The White House statement expressed appreciation for Abe’s “strong leadership’’ on a wide range of issues from typhoon relief in the Philippines to the Ebola response and the international fight against the Islamic State group.

The U.S. hopes Abe will be able to win passage of a series of bills needed to expand Japan’s military role, so that it can play a bigger part in their alliance. A heated debate is expected when parliament takes up the legislation, likely after local elections in April.

Kyodo news agency estimated voter turnout at 52.7 percent, a post-World War II record low and down nearly 7 percentage points from the previous lower house election in 2012. (AP)