ROME (AP) — Former Italian Premier Matteo Renzi has left the ruling Democratic Party to set up a new centrist force, in a risky move that further weakens the already shaky government forged only two weeks ago by the center-left Democrats and the populist 5-Star Movement.

Renzi announced his departure with a Facebook post on Tuesday morning, after explaining the abrupt move in an interview with Italian daily La Repubblica. He wrote "I have decided to leave the PD (Democrats) and to build together with others a new house to do politics differently."

The former premier has recently regained a central role in Italian politics, using his influence in parliament to push for the coalition deal between the Democrats and their former arch-enemies, the 5-Stars, in a last-ditch attempt to avert an early election and the likely triumph of Matteo Salvini's right-wing League party.

Political analysts say Renzi's U-turn has caught his enemies off guard, but is unlikely to boost his very low popularity ratings.