Paul Lamb has adopted the legal fight of locked-in sufferer Tony Nicklinson, who was left paralysed after suffering a stroke in 2005.
Mr Nicklinson broke down in tears on August 16 last year as he told ITV News he was left "devastated and heartbroken" at the High Court's decision to deny him a right to die.
Within days, Mr Nicklinson's health rapidly deteriorated after he contracted pneumonia and began refusing food. He died on 22 August 2012.
More top news
In Edinburgh tonight you can hear it and feel it. The buzz, the banter of the day and the thrilling sense something big is coming tomorrow.
There is nervousness, anxiety and on the streets of Edinburgh fuelled by an atmosphere unlike anything seen before in recent UK politics.
How will the vote go? What would a Yes victory do to England? Policital Editor Tom Bradby answers readers' questions on the referendum.