A power-sharing deal between Mauritania's military rulers and their political opponents is being delayed by disagreement over the composition of an interim government.

More than one week after agreeing to a transitional Government of National Unity, Mauritania's military rulers and their political opponents are still arguing over its make up.

The interim administration was to have been established last Saturday with the civilian president toppled in last August's military coup as its head. But Sidi Ould Cheikh Abdallahi must first formally resign as president, and he wants to do so in the office he was driven from by General Mohamed Ould Abdel Aziz.

Aziz objects to President Abdallahi returning to the presidency to step down, especially as Abdallahi's spokesman says the president intends to announce that doing so shows that the Aziz coup has failed.

Aziz nominates the transitional government's prime minister, but his opponents are objecting to the return of current prime minister Moulay Ould Mohamed Laghaf because he was part of the ruling military council's government.

So far there has been no opposition to the coalition of parties that is backing Abdallahi nominating the same Interior Minister who was toppled in the coup. It is a key post that will supervise the July vote.

The Ministers of Finance, Defense, and Information go to the rival opposition party, the Assembly of Democratic Forces. Party leader Ahmed Ould Dadah is now a presidential candidate as well after leading the opposition boycott of an Aziz-organized election that was cancelled as part of the power-sharing agreement.

Joining Aziz and Daddah in the presidential campaign is former military ruler Ely Ould Mohamed Vall, who has criticized Aziz for toppling Abdallahi's civilian government that came to power in elections Vall helped organize.

Supporters of another former military leader - Moauiya Ould Sidi Ahmed Taya - are calling for his return from exile in Doha so he can stand as a candidate in this vote as well.

Multilateral groups that helped broker the power-sharing deal in neighboring Senegal are working to see that it does not collapse. Members of the International Contact Group for Mauritania are expected in Nouakchott Saturday. Senegalese Foreign Minister Cheikh Tidiane Gadio arrived late Friday after talks in Washington with U.S. Secretary of State Hillary Clinton.

The African Union says the July 18 vote should not be delayed. The European Union says it will support the transitional government by gradually resuming development assistance.