ok here goes,
there is no nationalised "ambulance service" there are 13 regional ambulance trusts that are responsible for providing 999 services, they are discrete individual NHS "businesses" and as such there are differences between trusts. as with the rest of the NHS there are strict money issues which lead to some cutbacks, again it depends which trust you look at to see where they save money (staff training, equipment etc). Performance is managed by a national target called ORCON, 8 min response time for "life threatening" calls 30 mins for less urgent "emergency" calls, financialy penalties are based on the trust reaching this in 75% of all calls - therefore ORCON is GOD. note the use of quotation marks as there is often little similarity between the category of the call and how ill/injured the patient actually turns out to be!
Nationally there is a bit of a crisis, there aren't enough paramedics to go around, much the same with nursing, there simply isn't the structure to put enough students through quick enough to off set those that retire (at 68 now!) and those that change career (of which there are a vast amount) nursing plugs the gap with staff from outside the UK but there is limited scope to do this for paramedics as there are only a few other English speaking countries that have an equivalent scope of practice for their pre hospital staff (Aus and NZ being about it!). Morale is generally low, there is an increase in demand by about 6% every year, and at times (especially in london) demand far outstrips resources, to a point where it has become dangerous for both staff and patients. it is a vastly different job now than when I started, and the pressure can take its toll. historically there has been little done to address this only now is it becoming less of a Taboo within the service and some steps have been taken to safeguard the workforce in a more proactive way.
There is a lot more clinical responsibility now with paramedics practising at a level that isn't really comparable to any other area of the NHS. and this is beginning to be recognised outside of the Amb service. often other healthcare professionals see us as mere "ambulance drivers" (including the Minister for Health Jeremy *unt) but Paramedics are now getting opportunities to work in hospital resus rooms, cardiology units, GP surgeries, Minor Injuries units etc. there are also specialist roles within the Paramedic profession - there is the HART (or SORT) teams who do lots of sexy fireman training and strut about in green nomex and have lots of shiny kit, the Critical Care paramedic role specialises in the sickest/most injured and the role I do - "Practitioner in Urgent and Emergency Care" is more focused on treating minor injuries and health problems in the community. Bear in mind these roles will only be open to those with experience and mean you go back to uni for another 2-3 years (albeit on a part time basis).
depending on trust there are two routes to the title of Paramedic (its protected and you have to be on a register to call yourself one) both require a BSc from one of the unis around the country that run the courses.
1: external student - apply to uni and go through the 3 year degree course and then apply for a job as per usual graduate process, some unis are NHS funded (reduced or no tuition fees) some are up to 9k a year.
2: Some trusts will put employees through the degree course - so you could apply to a trust that does this for a lower grade role (what used to be called EMT) and hope you can get selected.
bear in mind that for some reason the courses are VERY popular - often applications in the 1000s for 30 places per year!
hope this helps...