In a strongly worded attack on Glasgow City Council, the Glasgow-born author said the cost-cutting plans were beneath contempt and urged members of the public to join his fight.
A letter he has written to The Herald has been co-signed by fellow authors Bernard MacLaverty, Alasdair Gray, Scottish Makar Liz Lochhead, and poet Tom Leonard.
MacLaverty said yesterday: "I know a number of people who benefit from this and it is something that you would hate to see stopped."
The council is consulting on plans to close centres in Cardonald, Summerston and Hinshaw Street which, alongside four other centres, cater for more than 500 people.
The union Unison has threatened to complain about the closures to social-work watchdog the Care Inspectorate.
Glasgow City Council says the centres are in poor condition and only offer limited services. It said the reforms would maximise opportunities within a wide variety of community settings and promote social inclusion for those with learning disabilities.
Kelman said: "This cynical disregard for the lives of one of the most disadvantaged sections of our people cannot be tolerated. Yet it follows the council's closure and destruction of the Dalmarnock day centre a few months ago.
"Why? To create a car park for visitors to the Commonwealth Games. It is beneath contempt.
"Those day centres represent the one place people with learning disabilities have where they are able just to be with friends, and in their own community."
He said the council had "judged this one community and condemned it, and is now in the process of destroying it. It is a brutal assault, the mark not only of the bully, but the coward.
"People with learning disabilities need the rest of us to stand alongside them and their carers, and defend their right to this quality of life."
Under the plans, people with the most complex support needs will use council-run centres in Riddrie, Carlton, Pollok and Jordanhill. The remainder will have support in the community.
The council says the number of people using council day centres has dropped significantly recently and many spend hours on public transport each day travelling to the centres.
A spokesman for Glasgow City Council said: "A consultation is now under way and we are working to a detailed plan that aims to bring forward views from the widest possible range of stakeholders.
"We see input from service users, carers, trades unions and others as being is an essential part of the consultation process.
"The results of the consultation exercise will be included in a paper with clear proposals for the way forward on learning disability day services, which it is hoped will go to the executive committee in January when a decision will be taken."
Tommy Gorman's daughter Patsy, 21, attends the Summerston centre two days a week.
Mr Gorman, from Maryhill, said: "Families are now wandering around shopping malls and gardening centres looking for things to do.
"You are going to have 300- plus disabled people wandering around Glasgow. It is a disaster waiting to happen."