The Liberals welcomed Tom Osborne to their caucus Thursday on the party's Twitter feed.
The member for St. John's South quit the Tories last September to sit as an Independent, saying he never supported Kathy Dunderdale as party leader.
His decision was seen as a crack in the Progressive Conservative caucus as polls suggested Dunderdale's popularity as premier was sliding.
Dunderdale said she never heard any complaints from Osborne until he quit the party and she revealed he had been angling for a cabinet post six months before he left her caucus, which he denied.
Osborne served as health and justice minister under former Tory premier Danny Williams before he was dropped from cabinet in 2007 after what he said was a heated disagreement.
Despite that rancour, Osborne said he still respected Williams as leader.
Osborne was first elected in 1996.
When he left the Tories he said he would consider joining the Liberals or NDP after consulting his constituents.
The Progressive Conservatives have a strong majority in the legislature. The Tories hold 36 seats, the Liberals have seven seats and the NDP has five seats.