Concluding instalment in Hogwarts franchise postponed to make way for Beginning of the Great Revival: The Founding of a Party

The wizard Harry Potter is being forced to make his farewell as a pirate in Beijing because China is holding back the official version of the concluding episode in the Hogwarts franchise in favour of an epic celebrating the 90-year-old Communist party.

Counterfeit DVD hawkers are selling poor-quality copies of the Deathly Hallows 2 in the capital days after its release in foreign markets.

The original will not be screened for a fortnight, at least partly due to the priority put on the big-budget political epic Beginning of the Great Revival: The Founding of a Party, which brings together more than 150 Chinese stars, including Hollywood icon Chow Yun-fat, in a two-hour tale of the Communist party's roots.

With its depiction of the romances and idealism of a young Mao, the story aims to attract a new audience to the party, which marked its 90th anniversary on 1 July.

With enormous political prestige at stake, China's film authorities have gone out of their way to ensure success for the movie, which premiered last month. The biggest potential foreign rivals have reportedly been delayed to allow a clearer run at the box office. Deathly Hallows will be released on 4 August; Transformers: Dark of the Moon on Thursday , three weeks after its release in the US. To protect the domestic film industry, only 20 foreign films are approved for release in China each year. Film industry observers say it is customary for the authorities to give preferential treatment to Chinese revolutionary and historical films.

"This practice is long-standing. Unlike the US, films are not treated just as consumer products in China. More importance is given to their role in shaping opinion and educating the public," said Li Hongyu, a film journalist for the South Weekend newspaper. "But the situation is better than it was 10 years ago. At least the Communist party no longer requires its members to go to the cinema for certain movies."

Harry Potter fans have joked that their best option was to help the Communist party achieve its goal – purportedly 800 million yuan (£77.5m) – ahead of time.

"The fans of Transformers and Harry Potter should join forces and encourage their dads, mums, uncles, aunts, grandfathers, grandmothers, etc to see The Beginning of the Great Revival. Then we won't wait until August," blogged Gudushizhe88 on the Baidu Tieba web forum.

The official Xinhua news agency says the historical extravaganza earned $46m during its first three weeks – not far from the record pace the authorities had aimed for.

Critics insist this is due to block-ticket buying by state-run firms and local governments, such as the northern city of Changchun, which reportedly bought tickets for 100,000 party members. The true figures may never be known. Popular websites have been ordered to disable their ratings and comments sections. Some netizens have posted photographs of doctored tickets for different films – such as Kung Fu Panda 2, Fast Five and the latest Pirates of the Caribbean – that were sold in the name of "Great Revival" in an apparent attempt to manipulate audience numbers. China Film Group, which produced the movie, denied that cinemas had been pressured to bump up the box office numbers.

Even if official sleight of hand conjures up impressive box office figures for the communist epic, the marketing magic of Harry Potter could yet prevail – at least on the black market.

"Harry Potter brand new. Good copies. Just 10 yuan," said an illegal hawker outside Beijing's Silk Market as he pulled out a large bundle of pirated movies, including the latest Pirates of the Caribbean, Cars 2 and The Mechanic. Great Revival was not among them.

Additional reporting by Cecily Huang