Santos, the national president of Kampi, has been in close contact with President Arroyo, the sources said.
Santos has been busy helping in the campaign of the administration’s People Power Coalition (PPC) which is at present undertaking the so-called "victory run" in the run-up to the May 14 elections.
Santos has been representing Mrs. Arroyo in the PPC rallies.
Sources said the initial plan was to make Mrs. Arroyo concurrent interior and local government secretary.
However, with the attempted takeover of Malacañang by Estrada loyalists and other developments, the sources said Santos emerged as the right man for the department.
Santos, a World War II veteran, also served as police chief of Davao City. He went into retirement in his farm in the outskirts of Davao City after serving the interior and local government department.