Eric and Ernie at Thames Television: 1978–83

In January 1978, just after their record breaking 1977 Christmas show, the pair left the BBC for ITV signing a contract with the London station Thames Television, which made front page news. Reasons given were a higher salary but crucially the clincher was the opportunity to make another movie, something Thames could offer through their Euston Films subsidiary. Eddie Braben, however, opted to remain at the BBC (signing an exclusive contract with the corporation shortly thereafter); Barry Cryer and John Junkin were brought in to contribute to the early Thames shows (Braben eventually made the switch when his BBC contract expired).

However, once more the stress of being such a popular entertainer affected Morecambe and his health. His wife Joan recalled that he would start worrying about the Christmas Special in June, and would frequently worry himself about how a certain routine would work. As a result, and probably because his heart had been damaged by the first attack ten years earlier, he suffered a second heart attack at home in Harpenden, Herts in January 1979, which led to a heart bypass operation by Magdi Yacoub in June 1979. After the heart attack, Morecambe asked Yacoub what would happen if he didn't have the operation, then in its infancy. Yacoub replied that he wouldn't expect Morecambe to live for more than a few months. Morecambe answered, "What are you doing this afternoon?"

Morecambe increasingly wanted to move away from the double act and into writing. In 1980 he played the Funny Uncle in a dramatisation of the John Betjeman poem "Indoor Games Near Newbury", part of an ITV special titled Betjeman's Britain that also starred Peter Cook and Susannah York. That saw the start of a relationship with producer/director Charles Wallace that led to a follow-up in 1981 for Paramount Pictures titled Late Flowering Love that saw Eric play a WWII major. The film was released in the UK with Raiders of the Lost Ark and many others, becoming the most successful UK short film ever. The project spawned two more solo performances. In 1981 Morecambe published Mr Lonely, a tragicomic novel about a stand-up comedian. He focused more on writing during what were to be the final years of his life.

Morecambe and Wise made a series for showing during the autumns of 1980 to 1983. They also appeared together recalling their music hall days in a one-hour special on ITV on 2 March 1983, called Eric & Ernie's Variety Days. During this time Morecambe published two other novels: The Reluctant Vampire (1982) and its sequel, The Vampire's Revenge (1983).

Morecambe and Wise's final show together was the 1983 Christmas special for ITV. Many believe that, had he lived longer, he would not have recorded another series because of worries about his heart. He was quoted as saying to his wife that "If I have another heart attack it will kill me, and if I do another Morecambe and Wise series, I will have another heart attack."

Morecambe and Wise worked on their much-desired film, a television movie in 1983, Night Train to Murder, with which both were unhappy: recorded on videotape using the new medium of lightweight ENG cameras instead of 16mm or 35mm film, they felt it looked "cheap". It was broadcast on ITV in January 1985. The final piece that Eric did (without Ernie) was a short comedy called The Passionate Pilgrim in which he was joined by Tom Baker and Madeline Smith. Again produced by Charles Wallace for MGM/UA, it was released in the cinema with the James Bond film Octopussy, and later Wargames. Wallace and Eric were half way through filming a fourth film when Eric died. It was never completed.