The ruling Liberal Democratic Party now has a majority in the Upper House for the first time in 27 years after a former opposition lawmaker was welcomed into the fold over weekend.

The new member cleared on Saturday gives the LDP a simple majority and provides Prime Minister Shinzo Abe with an even firmer grip on power as he pushes to revise the Constitution, experts say.

The party came up one seat short in the Diet’s 242-seat upper chamber after the July 10 election, but on July 12, former reconstruction minister Tatsuo Hirano was invited to join the conservative party after meeting with LDP Secretary-General Sadakazu Tanigaki.

Hirano, representing Iwate Prefecture, had been an independent since bolting the former Democratic Party of Japan three years ago following its trouncing in the 2012 Lower House election. The DPJ merged with a smaller party in March and was renamed the Democratic Party.

The pro-revision forces, including the LDP’s junior coalition partner Komeito, Initiatives from Osaka, and Nihon no Kokoro o Taisetsu ni suru To (Party for Japanese Kokoro) control 162 of the 242 seats in the chamber.

To propose a constitutional amendment and call for a national referendum, a two-thirds majority is required in both chambers of the Diet. The ruling bloc already commands such a majority in the Lower House.

Hirano, a three-term lawmaker whose seat was not contested in the latest election, was the DPJ’s minister in charge of reconstruction efforts for the 2011 earthquake and tsunami disasters before leaving in 2013 to become an independent.