Scott Lamb, 40, receives the highest level of Employment and Support Allowance, which is awarded to people doctors consider will not be fit ever to return to work.
However, he has been refused Disability Living Allowance, which his own doctor says he needs to assist with his mobility care.
Mr Lamb, from Cambuslang, injured his back in a fall nine years ago but continued to work as a care worker with deaf and blind people until last year.
He also has epilepsy, has suffered a stroke and takes a cocktail of painkillers to control the pain in his back. He needs crutches to keep him steady on his feet.
When he applied for Employment and Support Allowance (ESA) five months ago, he was successful and was placed in the Support Group – the highest level of assistance.
But he had already applied for the highest level of mobility Disability Living Allowance (DLA) and the middle level of personal care DLA last October and was refused.
He appealed and was refused again by an assessor at the Department Of Works And Pensions.
Mr Lamb, a father of two young children, said: "I have been told on one hand by the people who assessed me for ESA that I will not be able to go back to work, and, on the other hand, by the people who decide on DLA that there is nothing wrong with me.
"I am waiting for what I am told is very risky surgery to have two rods fitted to my spine and that will mean three months in hospital and years of extensive physiotherapy.
"One part of the Department Of Works And Pensions is contradicting the other and it feels like I am being kicked when I am down.
"I worked from the time I left school and never asked for anything. Now, when I need help, I am being refused."
Mr Lamb's MP, Rutherglen and Hamilton West's Tom Greatrex, has long campaigned against the UK Government's assessments for DLA and its use of IT firm Atos to carry out the assessments.
Mr Greatrex said: "Mr Lamb's case shows just how chaotic this Government's welfare policy is.
"One hand of the Department of Work And Pensions does not seem to know what the other is doing.
"When people are suffering from serious medical problems they should be helped by their Government, not hounded."
A DWP spokeswoman said she could not comment on individual cases, but said DLA assessments were not about questioning whether someone is disabled, but about care and mobility needs.
She added: "Disability Living Allowance is an outdated benefit, with the vast majority of people getting it for life without systematic checks to see if their condition has changed. This has led to hundreds of millions of pounds in overpayments.
"We are replacing DLA with the Personal Independence Payment and introducing a new face-to-face assessment and regular reviews, to make sure support is going to those who need it most.
"Under the new system, most individuals will have a consultation with a health professional as part of their claim, something missing right now.
"This will provide individuals with an opportunity to explain how their impairment affects their everyday lives, rather than trying to self-assess in an over-complicated application form."