The anniversary is meant to showcase China’s extraordinary rise from the ravages of war and famine to a modern, powerful nation state whose economic and military muscle is viewed by many with increasing concern.

This stunning transformation radically altered the social and physical landscape as hundreds of millions of rural Chinese poured into booming cities to power the “factory of the world” into the globe’s second largest economy.

Tuesday’s military procession across Tiananmen Square will showcase the army’s most advanced weaponry, including 160 aircraft, in a bid to drum up patriotic fervour and support for the Chinese Communist Party (CCP), with President Xi Jinping at the centre.

But the planned narrative has been disrupted by months of unrest in Hong Kong, a painful US trade war, international criticism of human rights abuses against Muslim minorities in Xinjiang, and soaring food prices.

Security has been ramped up ahead of the parade, with facial recognition, ID checks and searches for those entering Beijing by car, toy weapon sales banned and flying kites forbidden.

Roads have closed on weekend evenings for tanks to roll through in rehearsal. Fighter planes have roared in formation overhead.

Hundreds of thousands of government workers and students have been marching in practice, a participant telling the state-run Global Times they were given adult diapers as there was no time to take toilet breaks.

Twitter-like Weibo has been removing content that “distorts” the official narrative of history, while at least one human rights activist told AFP he was being forcibly sent out of Beijing during the celebrations.

“Xi and the CCP’s grip on power is strong. They have complete control over the media and more importantly the police and military,” said Eleanor Olcott, China policy analyst at research firm TS Lombard.

“The CCP, throughout their 70-year leadership of China, have inculcated a strong ethno-nationalism that remains the bedrock of their legitimacy and popularity.”