Former Prime Minister Yoshihiko Noda formed a new in-house group in the lower house on Wednesday with six other lawmakers, vowing to serve as a bridge between the two major opposition parties ahead of the upper house election in summer.

“We have to take a toll on the Liberal Democratic Party and put an end to (Prime Minister Shinzo) Abe’s administration in the election,” Noda said in a press conference.

Noda, who was in office between 2011 and 2012 under the then Democratic Party of Japan, stressed the importance of reuniting the leading opposition Constitutional Democratic Party of Japan and the second-largest party, the Democratic Party for the People, both of which are splinters of the now-defunct DPJ.

The new group with the Japanese name of “national council for revamping the social security system” seeks to compile policies focusing on medical reform, in particular preventive care, said the members including former Foreign Minister Koichiro Gemba.

The move came a day after former Foreign Minister Katsuya Okada and nine others joined a House of Representatives group associated with the CDPJ in the 465-member lower chamber, bringing the total number of the CDPJ camp to 68. The LDP group holds 282 seats in the lower house.

Both Noda and Okada belonged to the in-house group named the “Group of Independents” after the Democratic Party, the DPJ’s successor, disbanded in the run-up to the lower house election in October 2017.

Noda did not join forces with the CDPJ due to policy differences, including freezing the consumption tax hike scheduled for October this year. While serving as prime minister, Noda was behind the original government decision to raise the tax for fiscal reconstruction.