Job-seeking without any employment references can be extremely frustrating. Many companies tend to be wary of the unknown - recruitment can be an expensive business, so a candidate whose character can be vouched for will often be favourite.
Perhaps you have only recently arrived in the country, or maybe your previous references have moved on and are now out of contact, it may even be that you are planning to embark on a radically different career and therefore have no suitable referees to contact, but, whatever the reason, it is important be honest with any prospective employer. If you are, at least there is a chance they will look kindly on you and make you a job offer anyway.
The problem is that without a referee to explain whether or not you are suited to the work, the employer may lack crucial information about whether you would be good for the job. This may be especially problematic if you are applying for a position of responsibility - working with children, or in health & safety, for example.
Assuming that a reference is necessary (and in the majority of cases it will be) you should at least try to secure some character references. If these are from mature professionals (such as doctors, teachers, managers, etc) they could carry enough weight to satisfy an employer. You should also explain your situation to your local job centre as they may be able to intervene on your behalf to explain that you are planning to start a new career, etc.
If you are still struggling then perhaps you have to resort to applying for a less responsible position in the same field. This is obviously frustrating if you feel you are capable of more, but at least you will have a reference you can use as a key to the next level.