MANILA, Oct 5 (Reuters) - Philippine President Rodrigo Duterte"s government suffered a slump in ratings in the third quarter, with lower approval of its handling of issues like COVID-19, inflation, crime and corruption, an opinion poll showed on Wednesday. Pulse Asia"s Sept. 6 to 11 survey was released as election season gets underway in the Philippines for the presidency and hundreds of key political posts being contested in May 2022, including by Duterte"s allies. Duterte is allowed only one term in office and cannot seek re-election for the presidency. The drop mirrors a similar outcome of another poll published last month on public satisfaction with Duterte, whose score fell 21% in June from a record high in November. read more In Pulse Asia"s latest survey of 2,400 Filipinos, the Duterte administration saw double-digit declines in approval ratings for all 14 "selected national issues" compared to the same poll conducted a year ago. Those included fighting crime, corruption, managing inflation, and controlling the spread of COVID-19, compared with a poll done in the same month last year. Duterte"s closest aide, Senator Christopher "Bong" Go and some of his cabinet ministers are expected to file candidacies this week for the Senate and other positions up for election, which include seats in the lower house, governors and mayors.