Prime Minister Shinzo Abe’s ruling Liberal Democratic Party has extended its lead over opposition parties, according to a Kyodo News poll, as the campaign for the July 21 Upper House election heats up.

The latest nationwide survey, conducted for two days from Friday, shows support for the LDP has edged up 2.2 percentage points to 31.0 percent from the previous poll conducted on June 26 and 27.

The survey also found that 7.2 percent said they would vote for the main opposition Constitutional Democratic Party of Japan, down 1.8 points.

Some 5.6 percent said they support Komeito, the LDP’s coalition partner, unchanged from the June poll, followed by Ishin no To (Japan Innovation Party) at 4.4. percent, up 1.2 points, the Japanese Communist Party at 2.9 percent, down 0.5 points, and the Democratic Party for the People at 2.5 percent, up 0.9 points. Some 37.4 percent said they were undecided, down 1.8 points. The 17-day election campaign started on July 4.

A total of 2,359 people were contacted, with 1,229 answering questions.

One half of the House of Councilors’ seats are contested every three years. Due to electoral system reform, the total number of its seats will increase to 245 from the current 242 with the upcoming election, in which 124 seats — 121 plus an additional three — are up for grabs.

Voters will cast two ballots — one for a single-seat district and the other for a proportional representation block.

For the single-seat districts, 32.2 percent said they would vote for the ruling coalition of the LDP and Komeito, up 0.9 point, while 21.8 percent favored the opposition, up 1.5 points.

The approval rate for the Abe Cabinet fell 1.1 points to 46.5 percent, while the disapproval rate also decreased 3.8 points to 40.3 percent.

As a controversial government panel report that raised concerns about the country’s public pension system remains a key issue during the campaign, the survey showed 46.1 percent see the report as a point of contention, down 4.0 points.

The report said that an average retired couple would face a shortfall of ¥20 million under the current pension system if they live to be 95 years old. Finance Minister Taro Aso, who doubles as minister for financial services, said the report contradicts the government’s view.

While Abe is calling for more discussions on the revision of the Constitution during his campaign, 51.4 percent voiced opposition to an amendment, up from 50.1 percent in the previous poll.

On the government’s plan to hike the consumption tax to 10 percent in October from the current 8 percent, 54.3 percent expressed opposition, up 3.2 points.