Yes, especially in the cases of business careers. Marketing careers it's even more essential.
If you are fairly confident that you want to get a job in a business of any kind (literally, retail, marketing departments, publishers, any company with a large payroll) then you will need a degree in order to get anywhere. It is still just possible to do the 'trolley boy to vice president' journey, but you will spend most of your life working very physically demanding, very low paid jobs in order to make those promotions.
By contrast if you have a good degree from a respectable university then you will be able to enter a graduate training programme and within five years you could be earning over 30,000. For a little more information the average non-graduate salary would be at maximum 15,000 a year, and you'd be more likely to start out around 10-12 grand and have to work a second job to cover living expenses, or else live with your parents.
Our system is broken and it sucks but if you want to get anywhere without relying on massive amounts of luck then you will need a university qualification, along with taking several other short courses to boost your CV and provide you with more experience.
When a manager is looking over the CVs he's been sent, unless the job is something menial and physical (mail sorters, shelf stackers etc) then he will automatically reject anyone without a university (or at the least some form of vocational qualification in the chosen field) education.
EDIT: In terms of debt, you will come out with roughly 24,000 pounds of debt, but you won't get charged on it until you are earning over 15,000, and with a graduate degree you are (as previously mentioned) more likely to be earning over 15,000 very quickly. Once you have a graduate job, paying back your debt won't be as much of a problem as you think, because while there is a lower limit, you'll be able to reach it easily, and if you have a very well paid job then you'll be able to pay back more should you wish.
In terms of the general experience, I would say that, going into third year, university has been one of the most positive experiences of my entire life, I've learned a lot about the world, been very independent, and generally met some great people and had a fantastic time of it. If you get involved in things early (whatever your interests you will find a club or society or just a group of friends who are the same) then you will have an awesome time.
