Coronation Street legend Johnny Briggs is to set to leave Weatherfield after 30 years as Mike Baldwin. The actor will bow out after some of the most harrowing scenes ever shown on the soap as Mike loses his battle against bad knitwear - ahem, Alzheimer's disease.

Viewers have seen the factory boss become increasingly confused and forgetful in recent weeks. Over Christmas, fears for his health increase when he pops the question to lover Penny - then forgets he ever proposed. Doctors will eventually diagnose the incurable brain-wasting condition and over the coming months, Mike will be reduced to a shambling wreck.

A Street spokesman last night revealed: "His storyline has some way to run but he will be leaving in 2006 after completing 30 years in the show. It was his decision to retire." Johnny suffers from Seasonal Affective Disorder - a winter depression caused by lack of sunlight - and wants to spend more time in sunnier climes.