Are cats a threat to chickens?

[jan64]

I have 4 warrens that sleep in a small secure coop on a night, but I like to let them out every morning to free range in my back garden - their wings are clipped, and my fences are secure - but whilst sat out there watching them the other day, I noticed a neighbouring cat had appeared at one of my fences and was looking at the chickens, and now I'm nervous about them being out in the garden when Im not out there. My husband says that a cat would'nt attempt to attack them because of their similar size, but I don't know whether this is true or not?
I only have them roaming in the garden when I'm at home anyway - if I need to go out anywhere I put them back into the enclosure....any advice please?

 

[ShockValue]

Our cat stalks them, but has never attacked. Can't say for sure about "all" cats though.

 

[Happy Feathers]

The majority of cats carry a deadly bacteria in their saliva - "Pasteurella is a genus of Gram-negative, facultatively anaerobic bacteria" ( Wikipedia) Cats lick their paws so the bacteria is there as well. Pasturella will kill a small song bird in 2 to 3 days if the bird isn't given the correct antibiotic within the first 12 to 24 hours. When a cat scratches a human it can be just a dangerous and is commonly called "Cat Scratch Fever". Again, appropriate antibiotics are needed. (I know this from experience!)
I wouldn't run the risk of a cat playing with my chickens and accidentally scratching one.