"Sacking a minister while (he is) on a mission is un-Islamic, undiplomatic, offensive and outside the practices of politics," Mottaki was quoted as saying by the Mehr news agency on Sunday.
Ahmadinejad announced his decision to oust Mottaki on Monday while the 57-year-old career diplomat was on an official visit to Senegal.
"I was never told about the appointment of a new person within 24 hours of my departure for the mission," Mottaki said, referring to a meeting he had with the president on the eve of his departure, Mehr reported.
The country's atomic chief Ali Akbar Salehi officially took over on Saturday as the Islamic republic's interim foreign minister at a function which was also a farewell ceremony for Mottaki -- who shunned the reception.
"What is more ridiculous is that (I was not told about) the date for the farewell ceremony and the introduction" of Salehi, Mottaki said.
Responding to his remarks, a top aide to Ahmadinejad reiterated the government line that Mottaki had known in advance about his dismissal.
"Mr Mottaki was told about the change last Saturday, and he too expressed his readiness" to be replaced, senior adviser Mojtaba Samareh Hashemi was quoted as saying by the ISNA news agency.
Parliament speaker Ali Larijani on Sunday criticised Ahmadinejad's move, saying it had led to "inappropriate" judgments of the situation inside Iran.
"If the intention was to replace the foreign minister, it was only right to do it tactfully and respectfully with regards to the minister, not when (he is) travelling, which fuels inappropriate interpretations of the country's situation," ISNA quoted Larijani as saying.
Mottaki was sacked after he hailed as a "step forward" remarks by US Secretary of State Hillary Clinton that Tehran is entitled to a peaceful nuclear energy programme.
Clinton had told the BBC that Iran could enrich uranium for civilian purposes in the future, but only once it has demonstrated it can do so in a responsible manner and in accordance with Tehran's international obligations.
Mottaki appeared to cut across Iran's official position repeated almost daily that the country's enrichment of uranium is non-negotiable.
His sacking also came just days after Iran held crunch talks in Geneva on December 6 and 7 with world powers over its controversial nuclear dossier. Further talks are scheduled for next month in Iran's neighbour Turkey.
TEHRAN — (AFP)