Environment and Natural Resources Secretary Jose Atienza Jr. on Monday formally tendered his resignation as the DENR chief to concentrate on his Manila mayoralty bid in 2010.

“I tendered my resignation from the Cabinet to concentrate my time and effort for the preparation of my campaign,” Atienza said in a press conference at the DENR central office in Quezon City Monday.

President Arroyo has accepted the resignation of Environment Secretary Lito Atienza and plans to appoint an “insider” as his replacement, according to Press Secretary Cerge Remonde.

Atienza, who is seeking re-election as Manila mayor, said he had been discussing his resignation as head of the DENR with President Arroyo even before the holidays.

“It would be unfair if I will simultaneously do my work at the DENR and my preparation for the campaign,” he said.

He said that while elected and appointed government officials are not required to resign from their posts upon filing of their certificates of candidacy, as resolved by the Supreme Court, he said he decided to give up his post out of “delicadeza.”

Atienza said that resigning his Cabinet post will enable him to concentrate on the needs of Manila. “Manila is the face of the country, the microcosm of the country. I cannot take the very, very sorry state of the city now,” Atienza said.