When the Iraqi minister of state for tourism and archaeology affairs, Hashem al-Hashemy, was appointed acting oil minister last week, it was met by a collective shrug of the shoulders.

The sense of resignation, from the public and some politicians, could be because Mr Hashemy will hold the oil portfolio - where security and infrastructure problems have caused petroleum production to drop sharply in recent months - only until the formation of a new cabinet in the next few months. Or it could be that this case provides a perfect example of an inherent problem dogging Iraqi politics.

Seven weeks after elections, the main factions are engaged in intense horse-trading in which different ministries will be parcelled out among rival ethnic-based political parties - a practice that Iraqis agree yields bad government, yet one they continue to back.

With the next prime minister soon to be announced, members of the United Iraqi Alliance, the Shia Islamist coalition that dominates parliament, say they will make a decision on their candidate at the end of the week - most likely either Ibrahim al-Jaafari of the Dawa party or Adel Abdel Mahdi of the Supreme Council for Islamic Revolution in Iraq (Sciri).

Thanks to the UIA's parliamentary strength - 128 seats out of 275 - he will almost certainly be confirmed.

However, no faction in the UIA by itself controls more than around 30 seats. To put together the two-thirds majority necessary to form a government, the coalition's candidate will have to buy the support of its fellow Shia groups as well as Kurdish and Sunni Arab parties, each of which will demand its price.

After elections in January 2005 it took some three months for the UIA to form a government, while decisions went unmade and infrastructure contracts went unsigned. This time many observers expect the bargaining to take even longer.

Meanwhile, Iraqis say, the need to form cabinets by consensus produces a prime minister with little authority, presiding over ministers who are accountable only to their own parties rather than to the public at large.

Over the last few months, Iraqi party politics have caused chaos within the oil ministry with three ministers in two months.

Since the UIA came to power in January, the ministry has been considered the turf of the Fadhila (Virtue) party, a UIA partner that is particularly strong in the oil-producing province of Basra. However, the former minister Ibrahim Bahr al-Ulum, a one-time Fadhila ally, fell out with the government in December when he threatened to resign over a rise in petrol prices.

According to petroleum analysts, Fadhila was wary that the ministry might drift outside its control, and last week insisted on the appointment of Hashem al-Hashemy, a party member and the minister of tourism, who Iraqi oil officials say has no meaningful experience in their sector.

Since being ousted, Mr Bahr Ulum has spoken out against the spoils system. "It is not acceptable . . . that a party comes at the end of the government's [term of office] and imposes a name," he told the Financial Times. Nonetheless, the parties seem unlikely to relinquish control of ministries which are vital to building and maintaining a grassroots base.

In previous cabinets, some ministries - such as the Dawa-run health ministry of 2003-2004, for example - were notorious for requiring job applicants to bring a letter of recommendation from their local party office before they could be considered for a post. Bayan Jaber, the interior minister, of Sciri, meanwhile has been accused of filling government posts with his party's Badr militia.

Others are reported to have brought an ideological agenda to technocratic posts, such as Salam al-Maliki, transportation minister and a member of the radical Sadrist group, who once tried to mobilise a paramilitary force to seize control of the airport during a pay dispute with the contractor handling its security.

Even though other UIA members were said to be furious at Mr Maliki, his confrontational style plays well to his fellow Sadrists, who praise him as a man of "integrity" and say he should stay in his post.

The Shia are not the only players of the patronage game. Baghdad residents refer to the Kurdish-run foreign ministry as "little Irbil" - a town in the north - where Kurdish is heard more often than Arabic.

The new faces at the bargaining table this time around will be the Sunni parties, whose constituents largely boycotted the January 2005 elections but turned out in force in December. Many Sunni decry the factionalism of Iraqi politics, and say they want "non-sectarian" technocrats in the posts.