BRASILIA (Reuters) - Most of Brazil's governors are concerned about their state police officers appearing in an upcoming march in support of President Jair Bolsonaro, minutes published on Tuesday showed, as the far-right former army captain continues to sow doubt about next year's presidential election.

       Their concerns came to light in minutes of a Monday meeting of governors in Brasilia, in which they discussed a worsening political crisis in Brazil, as Bolsonaro picks fights with the Supreme Court and federal electoral authorities, and questions the credibility of the country's elections.

       Of Brazil's 27 governors, 25 signed the minutes expressing concern about the high level of support for the president among the country's roughly 500,000 military police.

       Active-duty military police are prohibited from making political demonstrations, but many are expected to show up at Sept 7 marches in support of Bolsonaro.

       Critics say Bolsonaro, who trails former leftist President Luis Inacio Lula da Silva in most opinion polls, is seeking to marshal cops' support ahead of next year's vote.

       His attacks on the electoral process have sparked fears he may not accept a potential loss. There is growing concern in Brazil about what role the military and state police could play if Bolsonaro were to reject the election result.

       Most experts believe the armed forces would defend the constitution and prioritize the peaceful handover of power, but some fear that state police officers could go on strike, essentially making the day-to-day running of states impossible for governors.

       "It is essential to reaffirm the governors' commitment to ensure that the mission of the state police takes place within constitutional and legal limits," the minutes signed by 25 governors say.

       The topic of Bolsonaro's support among military police was brought to the meeting by Sao Paulo Governor Joao Doria, a centrist rival to the president. On Monday, he fired https://www.reuters.com/world/americas/brazil-military-police-commander-fired-after-publicly-supporting-bolsonaro-2021-08-23 a senior state police officer who posted publicly about his support of the president and his plans to appear at the march.

       Doria said the upcoming "noisy demonstrations ... put democracy at risk."

       (Reporting by Lisandra Paraguassu; writing by Gabriel Stargardter; editing by Jonathan Oatis)