Peru’s Prime Minister Cesar Villanueva has stepped down, the government said on Friday, amid calls for President Martin Vizcarra to shake up his government and revive falling approval ratings. Villanueva, the prime minister for the past year, handed in his letter of resignation to Vizcarra, the president’s office said in a statement, confirming media reports earlier on Friday. The statement did not say the resignation was accepted but said Vizcarra thanked Villanueva for his services. A new prime minister has not yet been chosen but two government sources who asked not to be named told Reuters that Justice Minister Vicente Zeballos was under consideration for the position. Vizcarra will likely make several cabinet changes to revamp his team and shore up slipping support, the sources said. A survey by Datum Internacional published in local daily Peru 21 on Thursday found Vizcarra’s approval rating dropped seven percentage points from February to 56 percent.