His friends like Ron and Hermione would surely support him. They have been through a lot together, and they believe in Harry's leadership. Also, the Weasley family in general would be behind him. They have always been on Harry's side in his battles against the dark forces.
If Harry takes over the Ministry in the fanfiction, he could use his experience to better protect the wizarding world. He has faced Voldemort, so he knows the importance of unity. He would probably encourage more cooperation between different wizarding communities. He could also use his popularity to inspire young wizards and witches to be more involved in making the wizarding world a better place, like starting volunteer programs within the Ministry.
Hermione would definitely be one of his top allies. With her intelligence and knowledge of the wizarding laws, she could help Harry in making important decisions regarding Ministry policies. Ron would also be there, providing his loyalty and courage in times of trouble.
In the fanfic, Harry might take over the ministry to promote education reform. He could allocate more funds to Hogwarts and other wizarding schools. He may introduce new subjects like advanced Muggle studies to help wizards better understand the non - magical world. Also, he could create scholarship programs for students from underprivileged backgrounds.
He might meet Hermione. Since Hermione is always interested in academic things like Owls, she could be there to help Harry or just be involved in some research related to it.
Well, in this fanfic, perhaps Harry could face some unexpected challenges during the Owls at the Ministry. Maybe he discovers some new secrets about the Ministry's operations related to the Owls.
Perhaps he uncovers some major corruption or inefficiency in the Ministry. So, as a result of his efforts to reform it, he is given control. For example, if he finds that the Ministry has been misusing magic for personal gains, he could lead a movement to take it over and run it in a more just way.
In this fanfiction, it could be that Harry takes over the House of Potter to restore its former glory. He might have to deal with dark forces that have been lurking around the property, and he uses his skills and the help of his friends to cleanse it. Maybe he uncovers a plot against the wizarding world that was somehow connected to his family's house, and he has to prevent it from coming to fruition.
He might openly oppose their policies. For example, if the Ministry tries to pass a law that restricts the use of certain spells for self - defense, Harry could publicly speak out against it, giving interviews or writing articles in wizarding newspapers.
One possible reason could be the Ministry's corruption. In the original series, the Ministry often showed signs of being influenced by dark forces or being overly bureaucratic and not seeing the real threats. So in the fanfiction, this might be a driving factor for Harry to oppose them.