One of Britain's leading moral philosophers has called for a change in the law to allow assisted suicide in Britain following the death of paralysed rugby player Daniel James. Baroness Warnock, writing in today's Observer, calls for liberalisation of euthanasia laws on the grounds that 'we have a moral obligation to other people to take their seriously reached decisions with regard to their own lives equally seriously'.

Her comments come after Mark and Julie James were quizzed this weekend by officers. They had taken their 23-year-old son, Daniel, to a clinic in Switzerland last month where he became the youngest known Briton to have requested an assisted suicide. He had already attempted to kill himself three times after being paralysed from the chest down in a rugby accident.

Mary Warnock writes: 'The case of Mr and Mrs James ... presents a legal dilemma. Whether or not they are prosecuted, the law will be challenged. There are many, of whom I am one, who believe that we must try yet again to change the law, not by excluding from criminality those who assist death by taking the suicide abroad, but by liberalising the laws of our own country.'

Daniel James, who was described by friends as 'vivacious and warm' before his accident, was injured in March last year while training with Nuneaton Rugby Club. Despite numerous operations to fuse his vertabrae during eight months in hospital, he only regained limited use in his fingers. Last night, his parents were not responding to telephone calls at their farm near Sinton Green, Worcestershire where they live with daughters Georgina, 21, and Olivia, 18.

In emails sent in response to a euthanasia debate on a newspaper website, Mrs James criticised the well-meaning person who had alerted the police to Daniel's case. She wrote: 'This person had never met Dan before or after his accident and obviously gave no consideration for our younger daughters who had seen their big brother suffer so much and the day before had to say goodbye to him.

'I hope that one day I will get the chance to speak to this lady and ask if she had a son, daughter, father, mother, who could not walk, had no hand function, was incontinent, and relied upon 24-hour care for every basic need and they had asked her for support, what would she have done?!

'Our son could not have been more loved and had he felt he could have lived his life this way he would have been loved just the same, but this was his right, as a human being.'

In another email, she wrote: 'Whilst not everyone in Dan's situation would find it as unbearable as Dan, what right does any human being have to tell any other that they have to live such a life, filled with terror, discomfort and indignity? What right does one person who chooses to live with a particular illness or disability have to tell another that they should have to?'

Police yesterday were preparing a file for the Director of Public Prosecutions to decide whether Mr or Mrs James should be charged.