BISHKEK (Reuters) - Kyrgyzstan’s parliament approved plans on Wednesday to hold a Dec. 11 referendum on proposed reforms of the constitution that would strengthen the powers of the prime minister, parliament’s press office said.

Opponents of the reforms, which have been criticized by international monitoring bodies, say they are ultimately aimed at extending the rule of President Almazbek Atambayev.

Atambayev, 60, is barred by the constitution from running for a second presidential term when his mandate ends next year and critics say the proposed reform would enable him to become a powerful prime minister.

Atambayev has denied having such plans.

The government resigned last week after Atambayev’s Social Democratic party quit the ruling coalition because some partners refused to support the proposed changes to the constitution. It is now building a new coalition.

The amendments also include provisions granting more powers to the cabinet and to leaders of parliamentary factions.

In a joint comment, the Organization for Security and Cooperation in Europe and the Council of Europe said last month that the proposed amendments to the constitution would have a negative impact on the balance of powers by strengthening the executive’s powers at the expense of parliament and the judiciary.

Kyrgyzstan, an impoverished, mostly Muslim, nation of 6 million, has been volatile in recent years and was the scene of violent protests in 2005 and 2010 which toppled successive presidents.

If the confrontation between Atambayev and his opponents extends beyond a war of words and parliamentary maneuvering, it could destabilize the former Soviet republic which hosts a Russian military base.

During his rule which began in 2011, Atambayev has brought Kyrgyzstan closer into Moscow’s political orbit, securing Russian financial assistance and investments.

However, the sharp decline in oil prices has prompted Moscow to halt some ambitious projects such as the construction of hydroelectric power plants in Kyrgyzstan worth hundreds of millions of dollars. Many Kyrgyz migrant laborers have also lost jobs in Russia, increasing social tension.