The 1930s cinema in Warwick Road is set to be flattened by Manchester-based landowners Empera Estates to make way for a development of 82 flats.
However, campaign group Save Our Lonsdale hopes to ward off the bulldozers by getting the building listed, and has turned to a range of high-profile names for support.
The campaigners, led by former cinema usherette Linda Hargreaves, have now received the backing of both North West-based TV star Dodd and Clarence House.
Speaking to news agency 24dash.com, Hargreaves said: 'I wrote a letter to Ken Dodd and he wrote back saying that it is important that local people get behind the campaign and support it.'
The AJ has learned that English Heritage (EH) has submitted advice outlining the historic and architectural importance of the cinema to the DCMS, which will consider whether the building should be listed.
The Secretary of State will then make a final decision.
Meanwhile, it is understood that Carlisle City Council's planning committee has deferred a decision about Empera Estates' planning application until the EH report can be reviewed.
Although the cinema has been 'significantly altered' over the years, the building still boasts a number of original features, including a domed ceiling, a cast-iron lift and a stained-glass picture of Carlisle Castle.