* Shops staying open after 10 p.m. to be fined
* Could cut state's energy bill, break with chaotic past
* But grave doubts over whether rule can be enforced
* Failure would set bad precedent for bigger reforms
CAIRO, Oct 24 (Reuters) - Business has flourished for Cairo's store owners and itinerant street traders since a popular uprising ushered in 20 months of light-touch law enforcement, but the boom-time may soon be over.
A new government desperate to break with the administrative chaos that followed Hosni Mubarak's overthrow says it will enforce a national ban on late-night shopping next week and restore order to streets that have come to resemble vast open-air bazaars.
If the ban is enforced, it could cut an unsustainable state energy bill by shifting more human activity to daylight hours and shortening opening hours for power-hungry shops and stalls.
Some Cairo store workers welcome the prospect of a shorter working day. Some shop owners agree, but others say the ban makes no sense because most Egyptians want to shop late into the night.
``It is an appalling decision,'' said 28-year-old Mina Sabry, who sells women's clothes in a central Cairo mall. ``How can we close the shops from 10 p.m. when real work starts from seven?''
``Workers at the shops are happy with the decision because we will be able to leave early,'' said Ibrahim Eid, an employee at a shoe shop. ``Now we go home very late and transport is scarce.''
Shortly before 10 p.m. in Cairo's working-class neighbourhood of Shubra this week, streets were packed with shoppers bargaining with vendors.
As other north African cities go quiet after 10 p.m., much of Cairo comes to life with the din of car horns, the cries of street hawkers and music blaring from Nile pleasure boats.
Across Africa's biggest city, buzzing air conditioners cool shoppers and bright lights beam onto rows of mannequins wrapped in children's clothes, women's headscarves or gaudy underwear.
Families stay out late and babies can often be seen slumped asleep on the shoulders of window-shopping parents.
GOVERNOR NOT IMPRESSED
Many visitors enjoy the buzz of a city that comes to life in the cool of the night. Cairo's governor is less impressed.
``Who said Cairo is a night city?'' said the governor, Osama Kamal. ``If you mean tourism, tourism facilities are exempt from the decision. All countries in the world have a specific closing time for shops. We aren't inventing something new.''
He said Egyptians should go to bed early and wake up early so the country can focus on boosting productivity.
``You can't expect the guy who stays in the street till 3 a.m to wake up early and work,'' he said. ``There needs to be order.''
Kamal estimates that predecessors in his job have changed the rules on the hours of Cairo commerce eight times, but the regulations were only rarely enforced.
On Tuesday, the first working day after the Eid al-Adha holidays, police will begin handing out fines to any owner of a shop open after 10 p.m. and to cafes and restaurants that stay open past midnight, said Kamal.
After a second fine, the government might withdraw an offending shopkeeper's licence. The rules would not apply on weekends or holidays.
Success with the plan would suggest the new government of Islamist President Mohamed Mursi, the winner of Egypt's first free and fair elections for the leadership, was marking a clear break with its unaccountable predecessors.
Failure would suggest official foot-dragging and popular hostility to the police continue, setting a bad precedent for more vital reforms such as streamlining a bloated bureaucracy, cutting energy subsidies and rationalising taxation.
Some say the government is setting itself up for a fall with the new rules on shop closures.
It relies on a police force that has yet to regain full authority over the population since last year's uprising, which was driven partly by anger at a security establishment that routinely deprived citizens of their basic rights under Mubarak.
The government says the earlier closing times will save up to $6 billion annually.
Energy consumption is heavily subsidised by the state, but the cost has soared and the government needs to slash energy spending to balance its books and secure a $4.8 billion loan which it is seeking from the International Monetary Fund.
However, critics argue the government has chosen to fight the wrong battle.
``It is unrealistic because the police will not be able to force the shops to close,'' said Nabil Abdel Fattah from the al-Ahram Center for Political and Strategic Studies. ``It shows that those who proposed this are not qualified. They lack competence.''
Ahmed el Wakeel, head of the General Federation of Egyptian Chambers of Commerce, said the government had not waited for his organisation's opinion before deciding on the shop closures.
One economist said that what the government saves in energy costs could be lost elsewhere.
``It will have a negative effect on trade and will increase recession and unemployment as a result of cutting shifts,'' said economic expert and professor Hamdy Abdel Azim.
``When sales decline, profits will decline, taxes will decline and the losses will be with the state treasury.''