Pakistan’s former Prime Minister Imran Khan suffered a major blow months before national elections after one of his most trusted leaders quit his party and formed a rebel group in Khan’s stronghold northwest region.

Pervez Khattak, who served as Khan’s chief minister in Khyber Pakhtunkhwa from 2013 to 2018 and as the defense minister for the next four years, quit the former cricketer’s party in the “interest of the country,” he said in a video message from Peshawar, the capital of KP province. Local media reported he was joined by at least 57 ex-lawmakers from Khan’s Pakistan Tehreek-e-Insaf party.

The move comes weeks after Khan’s Tehreek-e-Insaf suspended Khattak’s party membership for criticizing his former leader for the attacks allegedly by Khan’s supporters on state and military properties across the country after his arrest on May 9. This is the second major breakaway group in about a month after many key leaders quit Khan’s party in Punjab, the biggest province.

Khan is facing more than 170 court cases ranging from corruption to murder and violence since he was removed from power in April last year in a parliamentary vote of no-confidence. Prime Minister Shehbaz Sharif, who took over from Khan, has said he will step down before the National Assembly completes its five-year term next month and the polls may be held by November.