Since your applying for 2015 surly thats plenty of time to work hard and get great AS results this year?
Most people will be applying for uni with only their AS grades.
However most people will have completed their 4 AS levels in a single academic year (whereas you appear to have completed two BTECs and are doing two AS levels in the 13/14 year?)
This could disadvantage you, depending on what you have been doing with the rest of your time. If you have competed these AS levels while traveling or working full time that would be understandable)
My advice would be to work like crazy and do AS Further Maths in time for the summer exams. If your not working full time with is very doable (if your ability in maths is sufficient)
If you get high UMS in maths, further and economics I dont see why they wouldnt at least consider you.