The couple, who have three children and live in Swansea, posed for local newspaper photographs, with Helen Knight pretending to care for her husband while he was comatose at home.
Prosecutor Jim Davis told Swansea Crown Court they went "to extraordinary lengths", adding: "The pair went to their MP and the local press to back their story that Knight was unfit to stand trial... claiming he was housebound, comatose and unable to communicate."
Knight was originally arrested for channelling £41,570 out of his neighbour's bank account, which he used to pay for holidays and to buy a caravan in Dorset.
Mr Davis said Knight first tried to dodge his fraud case in September 2012 by claiming he had been poisoned.
His wife told police he would "lie on a sofa all day in constant pain unable to move unaided".
She then claimed he was badly hurt when the garage door hit his head and he was in a coma. Mr Davis said: 'She said he was unable to stand trial.
"In the run-up to her husband's proposed trial in September 2014, Helen Knight began a furious campaign to get the trial derailed, writing to the Prime Minister, the deputy Prime Minister and her MP. They wanted to make sure the case was dropped. He spent more than ten weeks in hospital where he purported to show signs that he was in a vegetative state."
But a doctor said muscle definition in Knight's legs suggested he had been walking.
The court heard that Dr Sammy Wood told police he did not believe Knight was in a coma.
Mr Davis said when Knight was in hospital claiming to be comatose and quadriplegic, staff noticed drinking water from his bedside table "magically disappeared" overnight, adding: "Some staff spotted him walking."
The court heard he was seen on CCTV at the Severn Bridge and using his loyalty card at Tesco.
Each time officers tried to bring him to court, Knight's wife took him to hospital claiming his condition had worsened. But while he was under observation, he was seen eating.
James Hartson, defending, said the pair's lies were a "pathetic charade".
Knight was jailed for 14 months - to run after he has finished a four-and-a-half-year sentence imposed in November for the original fraud. His wife was jailed for ten months.
Both admitted perverting the course of justice.
- Daily Mail