How feasible is a 7 day NHS?

So, Jeremy Hunt, the Health Secretary for England and Wales, wants consultants to work a 7-day week, and is prepared to impose this. Simon Hamilton, the local Health Minister, agrees. This demand is based on there being 6,000 extra and unnecessary deaths (in England and Wales) when patients are admitted at the weekends. This assertion is questionable.
Elective patients are admitted during the week, and not so much at weekends.  Ancillary services in the community may be reduced at weekends; A&E departments traditionally are very busy on Friday and Saturday nights. Accordingly the ‘mix’ of patients admitted at weekends may differ from those admitted during the week.
What does this 7-day working mean beyond what already happens?
For example, some hospitals have a ‘surgeon of the week’ responsible for the daytime care of all emergency patients, so this surgeon will be in hospital at the weekends, often for much of the day. (During their week-shift, such surgeons don’t do any elective work.) And outside normal working hours, there is a shared on-call rota.
Will other surgeons be expected to do elective operations or out-patient work during the weekend?
Most ‘medical’ admissions are emergencies, but not all physicians can do all procedures. A patient admitted at a weekend might need, say, a cardiac angiogram, yet only some of the physicians can do this. What happens to such patients admitted at the weekends?
And consultants don’t work in isolation; teamwork needs nurses in theatres, in out-patients and in the wards; other consultants in pathology and intensive care, support staff such as secretaries, cleaners, porters etc. Under this base proposal they will all need to be there.
Some specialities don’t do much emergency work; but a patient might present with a strange rash, needing the expertise of a dermatologist.
Are these patients to wait until the next working day?
If there are, say, seven consultants in a speciality, then 7-day working must be spread amongst them, one fewer during parts of the working week.
 So if there is to be less work done during the week—will this be followed by complaints about facilities not being fully utilised? Is this another opportunity to present the case for further cuts?
What all this 7-day working disguises is the current lack of staff and facilities in the NHS compared to other westernised systems; it’s no surprise to me that so many medics are voting with their feet these days.