Opposition lawmakers immediately denounced the nomination, describing the vote as "an illegal coup".

According to the last amendment to the Constitution, the prime minister becomes acting president if the president is not able to fulfil his function.

Presidential elections are scheduled for 15vOctober and both Aliyevs have already signed in.

"Right now, it is a question of succession, nor function", commented one Iranian analyst of Caucasus affairs.

Besides being vice chairman of Azerbaijan’s State Oil Company, the younger Aliyev is also the president of Azerbaijan’s Olympic Committee and deputy General Secretary of the country’s ruling New Azerbaijan Party.

Heydar Aliyev, 80, is now in an Ankara military hospital. A Turkish doctor described his situation as "serious, but stable".

Waving flags and chanting "Freedom!" and "Down with the president!", about 4,000 supporters of four opposition parties demanded a fully democratic election to choose a new president.

While opposition media continue to insist that the president’s condition is terminal, Turkish websites as well as numerous unofficial sources claimed the 80-years-old Aliyev had died.

"We have some information that Aliyev is dead," said Arif Gadzhiyev, deputy head of the Mosavat opposition Party, as supporters waved the party's bright blue flag behind him.

But Mr. Mammed Aliyev, Azerbaijan's ambassador to Turkey, speaking on national television, denounced the reports as "lies and slander". He said they had been initiated by "media terrorists" in order to foment instability in Azerbaijan.

President Aliyev’s prolonged illness is raising the possibility of political confrontation and unrests in the oil-rich Republic of Azerbaijan. Already, authorities have stepped up measures designed to intimidate opposition politicians and journalists. There are indications that top administration officials are willing to explore even more drastic measures, including the postponement of the upcoming presidential election in order to retain power.

Local political analysts say Aliyev’s illness has already created a power vacuum that has great potential to result in political destabilisation. Some observers note that fissures in the ruling New Azerbaijan Party are already apparent.

Aliyev’s death could prompt political instability in the former Soviet republic, in which some major oil companies like the British Petroleum (BP) and other international oil groups have made big investments aimed at tapping reserves in and around the Caspian Sea.

"Advisers and bureaucrats long accustomed to obeying a single authority are suddenly rudderless, and no one seems to know who is in charge", a recent editorial in the independent newspaper "Azadliq" noted.

Although Ilham appears to be his father’s designated political successor, but opinion is reportedly divided within governing circles as to whether the younger Aliyev possesses the skills to manage a political transition. The lack of certainty over a successor has evidently sown indecision over the governing elite’s policy direction in the event of Heydar Aliyev’s death.

The bulk seems willing to go along with a dynastic transfer of power. However, some New Azerbaijani Party members appear willing to explore alternate arrangements. Musa Musayev, a member of parliament from the New Azerbaijan Party, publicly accused parliamentarians from his own party of starting secret negotiations with members of the opposition. Without naming names, he also implicated some ministers and heads of state-controlled companies in such discussions.

Many political observers in Baku believe that the government, in attempting to cast opposition leaders as agents of instability, is laying the groundwork for a full-fledged crackdown. Ilham Aliyev, in his public comments July 28, seemed to confirm that the government would explore all means to retain power.

"The only way for them [the opposition] to succeed is to create anarchy and unrest", Ilham said. "But we will never allow that. We will never let the opposition come to power. Their chances to come to power are equal to zero".

Reports that soldiers have been deployed in the capital, Baku, indicate that the government is preparing for any contingency. Yeni Musavat reported that a convoy of 50 troop trucks was seen entering Baku during the night of July 27. The newspaper also said that military units across the country have been put on alert.

Neighbouring countries of Turkey, Iran and Armenia in the one hand, supers powers such as the United States and Russia on the other, as well as major oil firms are watching carefully the unfolding of situation in Baku.

"A former top KGB officer, old Aliyev was able to maintain balanced relationship with the neighbours. Although he took secular Turkey for model, but at the same time kept normal ties with the Islamic Republic. Likewise, while he joined the rank of pro-American nations, he also established friendly relations with Moscow" and maintained the cease-fire with Armenia over the Upper Kharabagh enclave", the Iranian analyst observed.