Samia Nakhoul, William Maclean and Angus McDowall Reuters Saudi Deputy Crown Prince Mohammed bin Salman got a standing ovation when he visited a gathering of Saudi youth last month. Last week, after hearing about his economic plans in a meeting with religious leaders, one of the kingdom's most conservative sheikhs tweeted a smiling selfie of himself with the prince. Whether the 31-year-old son of King Salman will achieve his goal of modernising the kingdom’s economy is the subject of animated debate on social media, in office buildings and at coffee shops here. The plans, aimed at ending dependence on oil by 2030, require shaking up a bureaucracy that has stymied changes in the past, challenging powerful religious conservatives and building up a private sector currently reliant on state spending. Diplomats and economists say the programme, which relies on the private sector driving growth and providing new sources of revenue to the state via new taxes and fees, will be exceptionally difficult to implement. “Saudi Arabia is far away" from its economic goals, said Steffen Hertog, an economist at the London School of Economics (LSE) who studies the kingdom. The prince's close aides acknowledge the difficulties. Some ruling family members fear too rapid economic changes could cause social unrest or tension inside the Al Saud dynasty, Saudi analysts say. Yet in this country of 20 million Saudis and 10 million expatriates, the rise of Prince Mohammed -- who runs economic, defence and oil strategy -- underscores a dramatic shift towards a leadership seemingly more in tune with the needs of a country where 70 percent of the population is under 30. It is the first time that effective power has passed from the royal gerontocracy of 70- and 80-something rulers to a third generation of a family founded by the prince's grandfather, known as Ibn Saud. King Salman still has the final word, but he has delegated nearly unprecedented powers to his son. That has meant changes in style and substance. Prince Mohammed works 16-hour days -- unlike the more sluggish schedules of his older predecessors -- and has appointed business people and economic experts instead of other royals to top jobs. Many younger Saudis see the rise of a man who is usually referred to as "MbS" as evidence their generation is at last playing a role in a country whose patriarchal traditions had made power the province of the old. "I'm so excited! I want him to be our king now. I mean he's open-minded, has a great plan and maybe a little handsome," said Najla, 20, who did not wish to give her family name. That backing, and widespread fears about plunging oil prices, is providing MbS with an important springboard for his efforts. When in December, he and his team raised petrol prices -- a step previous administrations had hesitated to take for fear of public backlash -- Saudis took the move in stride. The lack of protests surprised MbS, according to people close to the prince, but also helped convince him that Saudis were ready for a change. Jihad al-Najjar, one of those who lined up outside petrol stations that night to fill up on the lower cost fuel, said he understood the country could no longer afford such subsidies. "It's not the real price," the 22-year-old medical student said. Abdulaziz al-Sager, head of the Jeddah and Geneva-based Gulf Research Centre, says there is a growing recognition among Saudi leaders that the oil-based economic system is not sustainable. That will necessarily lead to social and political change. "You cannot do the economic change and the transformation without some sort of political change," he says. "That raises the question of what sort of a new social contract we are going to have." CONFIDENCE Few had heard of Prince Mohammed before his father, 80-year-old son of modern Saudi Arabia's founder, became the kingdom’s 7th monarch in January 2015. Today, Prince Mohammed is second in line to rule behind Mohammed bin Nayef, a cousin who is crown prince and, as Interior Minister, head of internal security. Unlike many other royals, Prince Mohammed did not go to school abroad but graduated from King Saud University with a law degree. Informed Saudis who follow royal affairs say he is the favoured son of King Salman, who made him his personal adviser at a very young age. In his few public appearances with journalists, the powerful prince projects confidence. He listens to questions in English but speaks through the Royal Court’s interpreter, and sometimes corrects the interpreter's phrasing of English translations. His picks for top cabinet positions and senior advisers have leant more heavily on former businessmen than those of former administrations, which relied more on professional bureaucrats. Last week, Prince Mohammed officially unveiled Saudi Vision 2030, his blueprint to move the economy decisively from that he called its “addiction to oil” towards the private sector.