At a packed press conference held at his office in Wisma Darul Aman, Mukhriz said the resignation will take effect immediately.
He said he made the decision to resign as he has lost the majority support of assemblymen in the state assembly.
Mukhriz said he informed the Kedah Regency Council of his resignation on Tuesday.
"I feel a heavy burden shifted off my shoulders," he said. He said he also rejected an offer to be a deputy minister.