A St Leonards man who was allegedly refused benefits was sent a letter inviting him to appeal his case five months after his death.
James Oliver, 49, died on April 9, after a battle with chronic liver disease.
The former labourer’s brother Dave Smith, 53, said James was twice turned down for the Personal Independence Payment (PIP).
Just 12 hours before his death, Mr Smith said his brother told him he could not believe he was going to die yet was ‘not sick enough for PIP’.
However, five months after his death, the Department for Work and Pensions wrote a letter addressed to James at his old address inviting him to an appeal hearing in late September.
The letter was found by one of James’ six children, according to Mr Smith.
In a Facebook post, shared alongside a picture of James taken hours before his death, Mr Smith said: “I honestly cannot think of an organisation as shambolic, insensitive, incompetent and unhelpful as the DWP and the sooner all this PIP/Universal Credit fiasco is kicked into touch the better.
“To say I am angry is an understatement. How insulting for his kids too, one of whom found the letter addressed to their dead father.
“I am going to make this post public as I want the people of Hastings, and indeed the country, to see just what kind of slapdash operation the DWP now is.”
In the post, which has now been shared 119,000 times, Mr Smith said Hastings and Rye MP Amber Rudd was dealing his brother’s claim which he said had been declined twice.
He added: “Well her involvement has been so wonderfully useful they are still writing to a dead person at his original address even though they have all my details.
“Enough is enough. This has to stop.”
Mr Smith said he would take his share of his brother’s ashes along to the appeal hearing to ‘see just how responsive he is to their questions’.
Recalling his final moments with his brother, Mr Smith added: “One of the last things he said to us being ‘I don’t believe it. I’m going to die and I’m still not sick enough for PIP’.
“Well brother I’m still fighting for you and I will bloody win this for you if it’s the last thing I do.”
A Government spokesperson said: “Our thoughts are with Mr Oliver’s family at this difficult time.
“We are very sorry for the distress caused and are looking into this to prevent it happening again.”