Peer blighted by tragedy, the Earl of Northesk, dies aged 55

Sitting as a Conservative in the House of Lords, the earl had become a prominent campaigner in recent years against government plans for compulsory ID cards.

He had also spoken out against new laws that force internet service providers to store the records of their customers' online activities.

His life was blighted by tragedy in 2001, when his son and heir, Alexander Lord Rosehill, shot himself with his father's gun.

Born David Carnegie, he had been in the House of Lords since 1994, following the death of his father, the 13th earl.

The earldom was created in 1662, with the family seat based at Ethie Castle near Arbroath.

He was elected to remain in the House of Lords in 1999 when the majority of his fellow hereditary peers were removed.

His death will spark a by-election, in which Tory hereditary peers will vote for a replacement from among the ranks of hereditaries who do not have a seat in the Lords.

The government is attempting to use the Constitutional Reform and Governance Bill, which was first debated in the Lords last week, to end the system of by-elections.

The proposal, which is opposed by the Tories, would ultimately lead to the phasing-out of hereditary peers.

Lord Northesk and his wife, Jacqueline, married in 1979 and had five children.

His eldest son shot himself in the head with his father's gun in 2001, while on leave from a psychiatric hospital.

Alexander Lord Rosehill, 20, was on anti-psychotic and antidepressant drugs for a year before his death.

On the day of his death, his younger sister, Lady Sarah Rosehill, picked him up from Graylingwell hospital in Chichester, West Sussex. They went to the family's English estate at Haben Farm, Rogate, near Midhurst.

After playing a computer game, Lord Rosehill telephoned his father, then a Tory whip in the Lords, and his mother in the United States.

Shortly after the conversation, Lady Sarah found her brother dead in the attic.