LONDON (Reuters) - Dissident artist Ai Weiwei has had his run-ins with the authorities in his native China, but the Royal Academy of Arts is giving him all the space he needs for a mammoth retrospective opening in London on Saturday.

Among the works on display are security surveillance cameras, a pushchair and giant blades of grass, all carved out of marble, and a massive rolled-out map of China made of wood salvaged from dismantled temples.

Another room is hung with wallpaper with the repeated motif of a forearm and hand, with the middle finger up in the universally rude gesture.

Wallpaper in an adjoining room shows handcuffs and the Twitter social-media-site bird logo surrounded by CCTV cameras, all done in gold on a white background.

"We are expecting a lot of visitors to this show and as you can see, the spaces at the Academy I think have been brilliantly used by Ai Weiwei," Tim Marlow, the Academy's Artistic Director, said during a press tour on Tuesday.

Ai was unable to leave China for four years after his passport was confiscated at the airport when he was preparing to fly out of the country in April 2011. He was detained for 81 days after which he was released into a form of house arrest.

He worked with the Academy staff on the retrospective over the Internet and by phone, and through visits by curators to his home in Beijing.

When his passport was returned in July he was able to visit Berlin, where his son and partner live, and London to put the finishing touches to the exhibition.

At a press conference last Friday, Ai criticised the British government for not joining other nations including the United States, Canada,France, Germany and Australia, whose ambassadors he said had met with him in Beijing.

"I never met a British ambassador," he said. "They quite avoid to touch the issues relating to things which disturb."

Ai is not shy in dealing with politically sensitive matters in his work. One of the Academy's huge rooms contains his work" Straight" (2008-12), which comprises 96 tonnes of rebar concrete reinforcing rods collected from shoddy buildings that collapsed during the Sichuan earthquake of May, 2008, all carefully straightened and aligned on the floor.

On the walls are engraved the names of the thousands of victims.

The Academy says this is the largest British retrospective of Ai's work and includes pieces that have been seen before, notably at the Venice Biennale.

But even though Ai's passport has been returned, Marlow said he did not foresee a similar show in China anytime soon.

"I would imagine that if this work tried to be shipped back to China to be shown, there would be obviously no chance of that," he said.