Improve interview chances

Once you have found a contract which appeals to you, simply email your CV and Cover Letter to the agency advertising the role and follow up with a phone call to emphasise your interest in the job.  Agencies are usually bombarded with CV's for popular contracts, so telephone contact will improve your chances of getting an interview. Persistence will do you no harm.

The agent will only want to put forward candidates who are serious for the position and have maximum chance of securing the role. You might be the best qualified, but if the agent thinks someone less qualified will interview better or is more committed to the role then you could get dropped.

Avoid mentioning anything that might paint you in a negative light, for example "I have two other interviews this week", or "I'm not sure I'm fully qualified". You must remain positive and portray yourself as perfect for the role.