The use of legislation brought in to fight terrorism and serious crime against journalists has seen the UK slip four places down the World Press Freedom Index.
The annual report by Reporters Without Borders ranks 180 countries according to the freedom they allow journalists.
The UK ranks 38th and his behind countries such as Chile, Ghana and Uruguay.
Reporters Without Borders says of the UK: "Terrorist attacks have led to the adoption of draconian security legislation.
"The government reacted to the London public transport bombings in 2005 with a Terrorism Act the following year that restricts freedom of expression.
"The Regulation of Investigatory Powers Act (RIPA) adopted in 2000 allows the authorities to obtain the phone records of journalists in cases of threats to national security.
"Worse still, despite a law protecting the confidentiality of sources, the police have since 1984 been able to ask the courts to order media outlets to hand over unpublished journalistic source material 'in the interests of justice'.”
Last year it was revealed by the Interception of Communications Commissioner's Office that UK police forces had used RIPA against 82 journalists in the space of three years in order to secretly view their phone records and identify confidential sources.
Such requests now need external judicial approval, a system which is set to codified in the Investigatory Powers Bill which is currently before journalists.
The National Union of Journalists and others remain concerned that under the new system law enforcement bodies will make applications to view journalists' call records in secret (to telecoms providers) with no opportunity for news organisations to make the case against disclosure.
Under the Terrorism Act journalists can be forced by police to disclose material relating to sources who may be involved in terrorism.
Freelance security editor Robert Verkaik told Press Gazette last week: "If you say you've got a source and the information they tell you has some bearing on terrorism or intelligence then you can expect a knock at the door.
"I assume that everything I do on the telephone and everything I do on the computer is available. You have to assume that. From that basis you then decide how you make notes and how you write things."
Finland, Netherlands, Norway and Denmark take the top four places in the RWB index.
The worst countries in the world for press freedom (according to RWB) are Eritrea, North Korea, Turkmenistan and Syria.
RWB compiles its index by sending questionaires to experts in the various countries which are listed in the report.
RWB secretary general Christophe Deloire said: "It is unfortunately clear that many of the world’s leaders are developing a form of paranoia about legitimate journalism.
"The climate of fear results in a growing aversion to debate and pluralism, a clampdown on the media by ever more authoritarian and oppressive governments, and reporting in the privately-owned media that is increasingly shaped by personal interests.
"Journalism worthy of the name must be defended against the increase in propaganda and media content that is made to order or sponsored by vested interests. Guaranteeing the public’s right to independent and reliable news and information is essential if humankind’s problems, both local and global, are to be solved."
The UK has slipped down from 19th place in the list since 2000.
The illlustration above provided by RWB ranks countries according to the degree of press freedom (the darker the colour, the less press freedom).