It is a standardised award! It shouldn't vary! Else what is it's value? Standards are monitored by the National Qualifications Framework (Specifications and Benchmark Statements), which comprises a series of qualification descriptors to cover all awards from Certificate of HE through to Doctoral qualifications.
The only things that can stop you getting an honours degree is that you don't have enough credit points, dispite the grades you get for those you do take or that you don't do very well in your assessments.
If you can not argue your case to the examination board with regard to number of credit points, you might not even get an ordinary degree, and would end up with a Diploma/Certificate of Higher Education.
This is why places like Buckingham can offer a 2 year degree - they start credit points from day one, where as most univerities (OxBridge and their double first system is the only example I can think of) do a general 'bringing everyone up to the same level' easy first year, starting degree credit point awarding modules in Year 2.