As the resignation letter suggests, the disagreement over 'urban regeneration plan' and government intervention in the market as well as the ways economic affairs are organized are the main reasons of resignation.
Previously, he had resigned three times, but was rejected by the President. This time Akhoundi has asked Hassan Rouhani to accept his resignation as he is not able to align himself with the overall government policies.
Further he has mentioned that "three principles of rule of law, respecting property rights, and competitive market should not be violated".
So regarding different approaches of his view and the President, he believes his cooperation is not possible and morally right.
The President has accepted his resignation and candidates Mohammad Islami as the new minister to gain the vote of confidence from Parliament.