Uzbekistan's Senate, the upper house of parliament, has adopted a bill that would change the term in office for a president back to five years instead of the current seven-year term.
A national referendum in January 2002 approved changing the presidential term to seven years.
Incumbent President Islam Karimov has been elected once since then in 2007.
There are suspicions that Karimov, who proposed this change back to a five-year term, may use the amendment to seek two more terms in office.
Uzbekistan's constitution says a president may only serve two terms in office. Karimov, 73, has been elected three times, twice extending his term in office through referendums.
Other Central Asian presidents have used constitutional changes to justify seeking what could be anti-constitutional third or fourth terms, by claiming the amendments meant previous terms did not count.
The lower house of parliament already passed the amendment, which now only needs Karimov's signature.
compiled from agency reports