Japan is officially shrinking. Last October's census found 19,000 fewer Japanese than the previous year; the first time, barring the catastrophic year of 1945, that the population has dropped since censuses began in 1920. The peak population figure of 127.75 million may well one day be burned into the brains of future students. By 2050, the figure's expected to fall to 100 million and some predictions have the last Japanese switching off the lights sometime in the next century. Of course, such doomsday scenarios seldom materialise but the shrinking population already has consequences, notably on the country's creaking pension and health systems which face collapse under the strain of an inverted population pyramid. Other signs of strain are all around, for those looking. Old people died in the heavy snowfalls during winter because their roofs were laden with snow, said the former head of the Tokyo Immigration Bureau Hidenori Sakanaka. 'In the past, young people would have cleared that snow, but there are no youngsters left in the countryside.' Alarmed at such developments and the stubbornly low fertility rate - which slipped to 1.28 in 2004 - Mr Sakanaka recently poked his head above the bureaucratic barricades to suggest that Japan allow entry to 20 million immigrants over the next 50 years. Mr Sakanaka was then head of the Tokyo Immigration Bureau; a conscientious civil servant with three decades' experience of controlling the movement of people; not the most promising source for radical solutions to social problems. Yet amid the careful language in his book, Nyukan Senkih (Immigration Battle Diary), there was a startling, even utopian message: Japan must embrace multi-ethnic society and become a magnet for immigrants from all over Asia. The book followed a 2000 UN study which suggested Japan needed 310,000 immigrants a year. Mr Sakanaka, who retired last year and can be found behind the desk of the think-tank he directs, the Japan Immigration Policy Institute, said he wrote the book to spark debate. 'It's ultimately the Japanese people who will decide this issue, but the problem is that there is no debate,' he said. 'The population is declining and the birth rate is falling, and there is no way we will solve this just by encouraging more births. Now is our chance to begin talking about it seriously.' But discussion has been slow to ignite. An extract from the book ran in Chuo Koron magazine in 2004, there was a brief stir in the foreign media, then nothing. The book has sold less than 6,000 copies. In the meantime, Tokyo has introduced controversial revisions to the Immigration Control Law, to fingerprint and photograph all foreigners over 16 entering Japan. Civil rights' groups have reacted angrily to the plan, which comes just six years after Japan abandoned the practice of fingerprinting foreigners following years of protests. 'It's almost taboo to raise the issue of mass immigration here,' said Mr Sakanaka. 'Japan has no experience of this, only of sending people abroad. Modern Japan almost totally shuts out foreigners and the only people who debate the issue are specialists. Nobody is even researching it.' The taboo hasn't stopped the number of long-term resident foreigners in Japan from doubling, from 980,000 in 1989 to more than two million today, of whom 17 per cent are Chinese. But the foreign-born labour force of 800,000 people - many of whom work illegally - is still tiny compared with other advanced economies. Mr Sakanaka said clarity, not charity, should inform the debate. 'Here's the problem: The population of the world is over six billion, and about half of these people live in Asia,' he said. 'The population of China, India, Vietnam and so on is growing very fast, as ours is shrinking. We're a rich country surrounded by developing countries. 'If we just say we're going to stop immigration completely it will eventually overwhelm us, so we should deal with it now; open the taps slowly to qualified, distinguished people. It's like a dam; we're sitting behind it and a tsunami is coming. What are we going to do about it?' He said a clear immigration policy would save the economy and warm Japan's frosty relations with the rest of Asia. But he worries that public sentiment in Japan is growing more hostile. 'The common Japanese view of foreigners is very unsparing at the moment. Twenty years ago, three out of 10 people didn't like the Chinese; today it is seven out of 10. Many Japanese fear foreigners because they think they cause crime. 'Seventy per cent of Japanese are against allowing more tourists. That's ridiculous. Tourists don't cause crime and the overwhelming majority of foreigners are good people. But negative thinking about foreigners here is strong.' Why the fear? He said it was partly because of the way the issue was reported, but the lack of a support system for foreigners in Japan didn't help. This analysis hardly makes the ex-bureaucrat a socialist. The business Nikkei newspaper, which ran a 2004 editorial calling for an orderly opening of the labour market also said: 'Foreigners don't respect the rules and laws in Japan because they don't feel they are members of Japanese society. Unless the current system designed to shut out foreign workers is changed radically, the number of foreigners who have no interest in abiding by the law will only keep growing.' Polls suggest many Japanese hold contradictory attitudes. A Cabinet Office survey last year found more than 70 per cent worried that an increase in illegal foreign workers could undermine public safety, but more than 80 per cent said Japan should still accept more foreigners. The seeds of xenophobia are frequently spread by politicians, such as former trade minister Takeo Hiranuma, who raised the prospect of a blue-eyed foreigner muddying the 2600-year-old Imperial line. At a rally in February to protest allowing a female emperor to sit on the throne, he said: 'If [Princess] Aiko becomes the reigning empress, and gets involved with a blue-eyed foreigner while studying abroad and marries him, their child may be the emperor ... We should never let that happen.' Mr Sakanaka said the tipping point would come when the government developed political backbone. 'The politicians are afraid that if they speak positively about immigration they'll run up against public opinion,' he said. 'The politicians don't tackle it, the bureaucrats are divided among different agencies, and there is no policy, so who is going to start?' Two years ago, Mr Sakanaka met Shinzo Abe, the government's chief cabinet secretary and the man tipped to take over Japan's top political job when Junichiro Koizumi retires this autumn. He was unimpressed by Mr Abe's approach to what he calls 'perhaps the biggest problem facing Japan this century'. 'Mr Abe said: 'The foreign labour issue is very difficult and public opinion finds it difficult to accept. It is difficult for politicians to make the first move.' 'Someone should say: Look, there are good and bad foreigners. We won't solve this by ourselves, so let's discuss asking foreign labour to come here in greater but controlled numbers. 'But we haven't even got to the entry point of that debate.'