The science broadcaster and writer Simon Singh has been refused permission to appeal against a ruling in the libel case brought against him by the British Chiropractic Association. His case has aroused the anger of many in the science community, who describe the libel laws as encouraging the law courts to silence critics.

The ruling, made in May by Mr Justice Eady, said that an article by Dr Singh for the Guardian newspaper, published on 19 April 2008, was defamatory and alleged that the association was happy to promote bogus treatments (BMJ 2009;338:b2127, 26 May, doi:10.1136/bmj.b2127).

In the article (which has been removed from the Guardian’s website) Dr Singh criticised the British …