Background Checks By New Employer

Hi there, I was just wondering if it is legal for an employer to do Credit Checks on new employees?? I have just been offered a job after a period of self employment of 4 years. I desperately need this job as I have huge debts to pay from my failed business.
However, they have asked me to sign forms allowing them to do "background checks" As the job is in financial services (not retail banking) I am petrified that they will do a credit check on me. My credit rating is shot to pieces.
Thanks

Generally, financial service firms will not take on staff with financial difficulties that they have not been made aware of or are not being managed. This is for one of two reasons that I can see:
1. Staff in financial difficulties are a risk in terms of potential fraud
2. Reputational risk

The answer is yes - it is legal if you sign the form to permit them to do it. They cannot if you don't; however they will not proceed if you do not provide permission.