A file picture of Medvedev (left) and Luzhkov in Moscow. (AFP)

Moscow, Sept. 28: The mayor of Moscow, Yuri M. Luzhkov, a dominant figure in Russia in the two decades since the Soviet collapse, was dismissed today by President Dmitri A. Medvedev after questioning the President’s fitness and thus rattling the tightly controlled government here.

Officially, the Kremlin attributed Medvedev’s decision to his “loss of trust” in Luzhkov. But the two men had been feuding, and Luzhkov had seemed in recent weeks to be trying to create a rift between Medvedev and his mentor, Prime Minister Vladimir V. Putin, who is widely considered the country’s pre-eminent leader.

The conflict turned into a highly unusual spectacle because such defiance of the country’s leadership by a senior official rarely occurs in public.

Luzhkov had been under pressure to resign, but yesterday, declared that he would not. It appeared that Medvedev then had to move to avoid undercutting his own standing.

Medvedev, who was elected in 2008 and has championed policies to modernise the country, has been clearing away a generation of a older regional leaders who have long clung to power in Russia. The dismissal of Luzhkov is the most pronounced step yet in this campaign.

On a state visit to China, Medvedev told reporters today that he had no choice but to oust Luzhkov.

“It is difficult to imagine a situation under which a governor and a President of Russia, as the chief executive, can continue to work together when the President has lost confidence in the leader of a region,” Medvedev said. Legally, the Moscow mayor’s position is equal in rank to a regional governor

A current deputy mayor of Moscow was named temporarily to head the city while Medvedev considers candidates to replace Luzhkov.

Luzhkov did not immediately issue a statement. But leaders of Putin’s ruling party, United Russia, who had sat nervously on the sidelines while waiting for the dispute to be resolved, sprang to Medvedev’s defence and echoed the Kremlin’s remarks.

“We regret that one of the founders of the United Russia party, due to his own mistakes, has lost the trust of the head of the government,” said Vyacheslav Volodin, a party secretary.

Putin’s role in the quarrel between the President and the mayor has been the subject of intense speculation, and he also did not offer any comment today. But it seemed very unlikely that Medvedev would have dismissed Mr. Luzhkov without Putin’s assent.