A passionate supporter of Hampstead Theatre and an eminent lawyer has died the age of 74.

Michael Prior rose up the ranks in his family business to become one of the most respected solicitors in his field.

He was held in such high esteem that he was asked to pen crucial passages of an Act of Parliament and chaired committees at the International Bar Association.

Outside of work Mr Prior, from Church Row in Hampstead, was a fervent supporter of Hampstead Theatre at a time when the playhouse’s future looked uncertain.

He and his wife, Livia, helped in the fight to secure the theatre’s new building in Swiss Cottage.

Son Daniel Prior, from Tufnell Park, said: “For many years my parents were great patrons of Hampstead Theatre.

“They have supported it for almost as long as they have been here – they loved it and often manned the stall at the Hampstead Summer Festival.”

Mr Prior was born in Ilford in Essex, but his family moved to Surrey during the Second World War.

He attended Epsom College where he developed his love of all things French before hopping across the Channel to attend university in the late 1950s.

Mr Prior spent three years at the Sorbonne University in Paris, where he studied medieval literature.

His father called him back to England to work for the family firm William Prior & Co, qualifying as a solicitor in 1962.

He went on to hold positions on a number of prominent panels and committees related to insolvency. Mr Prior also wrote key passages of the 1986 Insolvency Act.

Son Daniel, 27, who works in communications, said: “He was extremely well respected and eminent and people often went to my dad for advice.

“He was still a consultant solicitor and people still asked for advice.”

Mr Prior and South African born Livia moved to Hampstead from Camden Town almost 30 years ago. He was chairman of the Church Row Association for many years.

The theatre-loving pair, who often went to the National Theatre in Waterloo, became deeply involved in the struggle to secure a new home for Hampstead Theatre, which for 40 years had been based in a portable building in Swiss Cottage.

The two donated time and money to the cause and helped secure the new building in 2003, which with its modern design and seats for 325 people, was a far cry from the original surroundings.

“He had such an enthusiasm for life and such a broad range of interests,” said Mr Prior’s son.

“He loved the theatre, but also he was a huge lover of sport, literature and history.

‘‘He had a real passion for life and so many people came up to me at the funeral saying, ‘He could never just be a supporter, he always wanted to participate and be involved’.”

Mr Prior died in a car crash near Stevenage on March 3.

It is believed he had a heart attack at the wheel and his Range Rover careered off the motorway and hit a clump of trees.

Mr Prior, whose funeral was held at Golders Green Crematorium last Tuesday (March 12), is survived by wife Livia and children Daniel, Candida, Tim, Charlotte and Caroline.