Straw constitution hint looms

In a speech to be delivered in Washington DC he will say that current constitutional reforms may only be a first step towards a complete overhaul of the UK's laws and principles.

Mr Straw will also acknowledge that some aspects of a country's constitution should change to reflect the modern world - a comment which is bound to be interpreted as a reference to the difficulties of dealing with terror suspects.

The minister - who oversaw the introduction of the controversial Human Rights Act when he was home secretary - is expected to place a new emphasis on the concept of civic duty, and suggest that an individual's obligations to society should be firmly spelled out.

He is expected to say in the speech at George Washington University that rights contained in any country's constitution "must modernise to reflect the world in which they operate".

The politician, delivering the keynote speech of a three-day visit to the United States, will suggest that there should be a constant programme of "maintenance" to ensure rights remain relevant to modern life.

He will say: "We now need to think very carefully about whether a British Bill of Rights and Responsibilities should be a step towards a full written constitution, which would bring us in line with the most progressive democracies around the world. But that is a debate for another time."

The Justice Secretary is already working on a new Bill of Rights and Responsibilities, which will attempt to counter the claims that human rights laws give too much emphasis to the rights of criminals.

Mr Straw, who previously opposed the idea of a written constitution, last year indicated that he had changed his mind, but his call for a debate on the matter marks a new chapter in Government thinking.

The existing British constitution is contained in a wide range of written documents - tracing back to Magna Carta in 1215 - and common law.