Armed with a doctor's certificate, recommendations from two psychiatrists and a straight-jacket, a group of campaigners will attempt to get Blair sectioned under the Mental Health Act (1983) when he gets back to Heathrow airport later this month. Under the Act, a person is subject to compulsory admission for assessment in a mental institution if a doctor fears they are "likely to cause harm to themselves or others".

Using their knowledge of the system they will attempt to force an emergency section. An emergency admission for observation under Section 5 of the Act lasts up to three days and can be sanctioned by one doctor. Admission under Section 2 can last for 28 days, whilst under Section 4 the patient can be detained for up to six months.

A consultant psychiatrist who asked to remain anonymous said today: "In Mr Blair we see an individual who believes he has been chosen by god, who holds to certain beliefs regardless of logic or fact, and who demonstrates an inability to empathise. These are classic symptoms of someone suffering from psychotic grandiose delusions.

"Under the Mental Health Act 1983 a person can be sectioned if they are likely to cause harm to themselves or to others. It is beyond dispute that Tony Blair has caused grievous harm to hundreds of thousands of people in Iraq in the past and unless he is locked away in a secure institution, he looks set to try and do the same again."