A new treason law must deal with those at war with their own state

SIR – Policy Exchange rightly notes that the Treason Act of 1351 is not “fit for purpose” (report, July 25).

It has not been used since 1945. With only terrorism laws as a substitute, there has long been a gaping hole in British law to cover those citizens who take up arms against their own state.

However, we should not “update” the 1351 Act but scrap it altogether. The notion that its archaic language or its purpose are ill-suited to the modern age is not at all new: the focus of the Act is overwhelmingly on an attack on the monarch (in contrast to modern treason laws on the European continent). Already by the 1790s, this made British treason law unworkable: the country faced new domestic and foreign threats. When William Pitt’s government tried to use the Act to prosecute radical reformers as “traitors”, it failed, as the prosecution strained to interpret the reformers’ aims as an attack on the king.

The 1916 treason trial of Roger Casement, for plotting with wartime Germany, might be thought more relevant to our age. Yet here too the prosecution had to strain hard to match his behaviour against the wording of the 1351 Act.

A completely new law, which targets the modern threats to Britain, is what is required. In our global age, such a law cannot seek to criminalise those many British citizens who have a wide variety of loyalties outside the country. But it can ensure that citizens like the jihadists of Islamic State of Iraq and the Levant, who actively plot or commit violence against their own home community, are brought to justice and severely punished. Professor Mark Cornwall

University of Southampton

SIR – Nick Timothy (Comment, July 26), in arguing that a successful prosecution of the two alleged jihadists held in or near Syria “would be far less likely here than in America”, refers to the 1999 case of Nicholas Mullen. In that case the Court of Appeal held that it would be an abuse of process to try the defendant after unlawful rendition from Zimbabwe.

Neither that case nor any other would inhibit a trial of the present suspects in Britain. Critical to Regina v Mullen, and cases that it drew upon and which followed it, was that the defendant had been brought to Britain in breach of extradition and deportation procedures – and, therefore, unlawfully. This is a common law doctrine, not derived from European human rights law.

Absolutely nothing would prevent a trial where no such procedures exist, as in the case of the anarchic state of Syria, or in other neighbouring territories with which no such arrangements are legally or practically available.

If the evidence exists to try these alleged terrorists, there is no basis for the resigned, defeatist argument that “it would be so hard to prosecute them at home”. Do we really have to defer to the US Department of Justice? Alun Jones QC

London WC1