Yemen's internationally recognised president sent a letter to the UN secretary-general criticising his envoy to the war-torn Arab country over allegedly siding with Iran-aligned Houthi rebels, the president's office said Friday.
Hadi also warned his government would stop dealing with the UN envoy.
"I can no longer tolerate the violations committed by the special envoy, which threaten prospects for a solution," read the five-page letter, a copy of which was released to reporters Thursday.
It also accuses Griffiths of treating the "rebels as a de-facto government and as an equal to the legitimate and elected government" of Yemen.
The conflict in Yemen began with the 2014 takeover of the capital, Sanaa, by the Shiite Houthi rebels.
A Saudi-led coalition allied with Hadi's government has been fighting the Houthis since March 2015.
The fighting in the Arab world's poorest country has killed an estimated 60,000 people and left millions suffering from lack of food and medical care.
Also on Friday, security officials in Houthi-controlled territory said a Saudi-led air raid killed eight civilians and wounded at least four in the southwestern province of Taiz.
The officials, speaking on condition of anonymity for fear of their safety, said the attack took place Friday in Mawya district.
Mohamed Abdel Salam, spokesman for the Houthis, condemned the attack.
Tensions arose between Griffiths and Hadi last week after the UN announced the long-delayed Houthi withdrawal from the flashpoint port city of Hodeida.
Hadi's government accused Griffiths at the time of turning a blind eye that the rebels had allegedly only handed control of the port to "militia leaders" loyal to them.
The "redeployment of Houthis" from Hodeida was part of a UN-brokered deal concluded in December.
Hadi went on to say that Griffiths' "poor understanding" of the Yemeni conflict makes him unfit for his post.
While briefing the UN Security Council on the situation in Yemen last week, Griffiths urged the warring sides to maintain the momentum of the Houthi withdrawal from Hodeida the country's lifeline to foreign aid and to work urgently on a political solution to the devastating conflict.
There were "signs of hope" but "also alarming signs" that could threaten progress, Griffiths said, a reference to continuing clashes in the southern Dhale province.
Later on Friday, Houthi rebel leader Mohamed Ali al-Houthi tweeted that Hadi's letter to the UN chief was "a miserable attempt to curtail peace.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)