You must call them. I'm sure I've read about animals being similarly restricted in small spaces who end up with ulcerated paws due to the acid in the urine they are forced to stand in.
If you call the RSPCA they can do a proper inspection and check the dogs for any other signs of neglect. Even if the owner lies when they call, it should be apparent from the state (and/or smell) in the porch that it's regulary used to confine them for long periods.
If that's the case, the knobhead owner is no doubt "protecting" the rest of the house from any damage or mess they might cause while he's at work. Makes me absolutely spitting mad that people take on large animals (or any animal) like that without thinking through the reality of caring for them responsibly.
I'd love to know what your definition of "neglect" is Alardi. Any animal needs free access to water at all times, never mind food, and, as I said previously, their physical health can be affected by standing in urine & faeces. That's not even taking into account the mental strain on intelligent animals being confined in a space which is clearly too small for them, and without any mental stimulation either. Two St Bernard size dogs in an average sized porch would be equivalent to you or I spending most of the day in a toilet cubicle.