The year began with journalists from China's Southern Weekly striking because their paper had spiked a leader calling for constitutional protections for individual liberty at the behest of the local propaganda chief – and replaced it with an article praising the Communist party. It ends with the New York Times and Bloomberg, having dared to publish details of the stunning family wealth of the country's outgoing prime minister and incoming president, fearing that the one-year ban on new journalist visas to both organisations may be continued.

This is life in a one-party state, a running battle between a party apparatus fearful for its legitimacy and journalists whose craft necessarily involves disclosing information that the party would rather nobody knew. The practice of journalism in China, a country where 30 practitioners are in prison, has never been easy. During 2013, it has become a great deal harder.

A new anti-rumour law makes spreading "defamatory" information on the internet that "harms the national interest" punishable with three years' imprisonment if there are more than 500 re-posts or 5,000 internet viewers. Ren Xianliang, vice-minister of the State Internet Information Office, declares that the control of "rumours" has been "quite effective", "slander" is in decline and the flow of information is more " orderly". He is creating "cyberspace with Chinese characteristics", he helpfully explains.

Every journalist in China knows what that means. Overstep the mark and you can, like Reuters' Paul Mooney, simply have a request to have your visa renewed turned down. Mooney had dared to be too critical. For Chinese journalists, the penalties are more dramatic. You can lose your job or you can be arrested and only released once you have made a confession of your wrongs.

Thus Chen Yongzhou, a distinguished reporter on Guandong's New Express, found himself arrested in October after he had exposed alleged corruption at a local state-owned construction equipment company – Zoomlion. The police who arrested him arrived in a car owned by the company. The paper called for his release, saying that it had checked all 15 reports and could only find one trivial error. But then Chen "confessed", broadcast on TV, that he had accepted bribes from Zoomlion's competitors to write the pieces.

He may have done – bribery is endemic in China and journalists do accept bribes to write stories that help their bribers' interests. On the other hand, arrest in China is terrifying; Chen warned after three days of custody that he could only "hold out" for another 30. The "confession" was delivered before any trial and the source of the bribe has never been identified. Everyone knows that the false accounting and excessive charging for which Zoomlion was criticised is common practice in state-owned enterprises, but you also have to be careful who in power you criticise. The New Express climbed down fast.

According to Wang Qinlei, a former producer at China Central TV's top political programmes, who was fired a few weeks ago for publicly criticising its coverage of the concocted attacks on a famous social blogger, political influence is everywhere. His blog was deleted almost instantly. "In the space of a year, we get upwards of a thousand propaganda orders," he wrote. "How many of these orders were issued in the national interest and how many were issued to serve the political and economic interests of some individual, group or leader? And how often did we castrate ourselves as a result of trying to fathom the attitudes of high officials? Our leaders should understand that if the amount of news you can't report climbs too high, people won't believe the news you can report – because it's propaganda chosen with a purpose."

President Xi's response is to require every Chinese journalist to take an ideology exam early next year in order to qualify for their press cards. The manual on which the exam is based insists that journalists must not deviate from the party line and that the relationship between the party and news media is "one of leader and the led". The aim is to make sure any successors to Wang and Chen know their limits. Self-censorship, after all, is much better than censorship.

This intensified drive to control the media has been accompanied by the arrest, detention and interrogation over the last two months of up to 300 lawyers and human rights activists, including Xu Zhiyong, associated with the movement to expose the dazzling family wealth of the elite who run China. After all, it was Bloomberg's and the New York Times' exposures of Xi's family wealth that got them into such trouble. Xi and his circle are keenly aware that the party is in danger of toppling into a spiral of delegitimacy with this as a touchstone issue, hence the extraordinary arrest last week for corruption of a former member of the politburo, Zhou Yongkang. Nobody this powerful has ever been taken on before.

The radicalism of 3rd plenum in November took many China watchers by surprise, but the party is in the last chance saloon. The moves to give rights to tens of millions of migrant workers, lift the one-child policy, reform state-owned enterprises and phase out labour camps were aimed at making the party more people-friendly. This is the new " line to follow" for Chinese journalists, coupled with ever more hysterical attacks on "constitutionalism", the universalism of human rights and Japan's alleged expansionism. No scrutiny of the fortunes of the elite is to be permitted.

The plenum did not go far enough; the entire Chinese structure, with a bankrupt banking system, is buckling. The party will sacrifice any freedom to try to save itself, yet it is with this anti-freedom, stricken China that the Tory party is now embarking on a love-in, driven in part by its near crazed Euroscepticism. David Cameron dropped any vestige of dignity in his recent commercial trip, shrugging off the Global Times editorial that Britain "is just an old European country apt for travel and study. This has gradually become the habitual thought of the Chinese people." Instead, anxious for business at any price, he declared: "Britain will be the main advocate of China in the west."

Perhaps Cameron and Xi have more in common than they declare. After all, Cameron leads a party, a large part of which wants to leave the European court of human rights and criticises the Guardian's exposure of industrial-scale state surveillance, as would the Chinese Communist party. God knows, the US has many warts, but on these issues at least it is prepared to challenge China. Britain should unambiguously be on the same side.