Iraq’s Supreme Federal Court ruled on Tuesday that no more candidates for president can be nominated.
The decision came after MPs failed to meet the deadline to elect the new President of the Republic.
Government formation in Iraq has stalled amid deepening political deadlock, months after the national election in October.
The court said a move to introduce new candidates to the race would be “unconstitutional”.
Last month, the legislative body approved a list of 25 candidates for the presidency, including current President Barham Salih.
It was supposed to vote on the names on February 7 but the bigger political parties boycotted the session due to divisions on the nominees.
The next day, Parliament Speaker Mohammed Al Halbousi reopened registration for candidacy.
“There is no provision in the constitution which gives the Parliament’s presidency the right to reopen nomination of the president post,” the court said in its ruling.
It is allowed to reopen registration only after a decision is approved inside the Parliament.
Although the position of president is largely ceremonial, the role must be filled as one of the constitutionally mandated steps for the formation of a new government.
The four-year post is usually held by a member of Iraq's Kurdish minority, although this is based on an informal agreement. Kurdish rivals have yet to agree on one nominee to back.
Tuesday’s ruling cast further doubt on the process of forming the new government, more than four months after October's national elections.
Parliament did not specify the mechanism of approving the decision to reopen registration, or the required quorum to pass it.
The two leading Kurdish parties, the Kurdistan Democratic Party and Patriotic Union of Kurdistan, have been at loggerheads over nominees.
The KDP, which swept the polls in the Kurdistan Region, winning 31 seats in the 329-seat Parliament, is keen to hold on to the post, nominating former foreign and finance minister Hoshyar Zebari.
The presidency benefits the KDP because the party manages the foreign relations of the semi-autonomous Kurdish region, while the Iraqi president often represents the nation on official visits.
While the Kurdistan Alliance is led by KDP rivals the PUK, the latter won only 17 seats and has nominated Mr Salih for another term.
This month, the Federal Supreme Court removed Mr Zebari over corruption and mismanagement-related accusations while in office. He has denied the charges, which he claims are politically motivated.
Then KDP then put forth a new candidate but the process has since stalled, caught up in a deadlocked government formation process.
