Former Democratic Party of Japan leader and political heavyweight Ichiro Ozawa resigned from the ruling party along with 49 of his followers on Monday in a protest against the government's sales tax hike proposal.

The move will trigger a party split and weaken the rule of Prime Minister Yoshihiko Noda, analysts said.

Among the 50 lawmakers who submitted their resignation letters to the party, 30 are lower house members and 12 are in the upper chamber. The number of DPJ members in the 480-member lower house will decrease from 289 to 251.