The family of a man who died after being attacked have launched a campaign called “One punch can kill”.

Ashley Mansell's family have written to the Prime Minister, Buckingham Palace, the NHS, Sussex Police and government ministers to raise awareness of the issue.

Mr Mansell, 30, of Brighton, died in April of a heart attack. In 2009 he had been punched in a park in Portslade and suffered critical head injuries.

His family including fiancée Zoe Later, 31, and sister Lucy Mansell, 25, believe his injuries led directly to him suffering the heart attack because he became less active and his health deteriorated.

He suffered permanent brain damage in the attack and was in a coma for ten days and hospital for months after being assaulted.

In November he returned to Hurstwood Park Neurosciences Centre in Haywards Heath for further treatment.

In the bed next to him was Tony Magdi, of Hove, who himself died later after being punched in the face.

Mr Mansell's attacker, James McCubbing, then 25, was convicted of assault and jailed for 40 months.

Mr Magdi's attacker Paul Lambeth, 36, of Stafford Road, Brighton, admitted manslaughter and was jailed for 18 months last week.

Mr Mansell's father, John Mansell, spoke of the “damage, heartache and sadness one punch can cause”.

A Facebook group has been launched in their memory which has quickly attracted more than 800 members.

James Mansell said: “One moment of senseless violence can cause a lifetime of anguish and devastates the victims' families.

“Publicans, bars, clubs and even restaurants should be made aware of their responsibilities in this area and refuse to serve people if they are drunk.

“Hopefully this will become a large enough group to be able to go to the police in Brighton and other cities and ask them to start a concerted and high profile campaign to make people aware of the fact that one punch can kill.”

Mr Mansell and Mr Magdi are not the only people to have died after being punched in Brighton and Hove.

In January 1999 Jay Abatan died after being punched twice outside the Ocean Rooms in Morley Street, Brighton.

Ricky Brown, 25, was fatally punched outside the same building in the early hours of January 1, 2010.