Russ is right.
I know that agency nurses in London get paid a minimum of at least £20 an hour and depending on their grade and speciality, up to circa £35 an hour.
Do not confuse this with the average wage of a recently qualified nurse in the NHS... it is considerably less. Because of this.... more and more nurses are leaving the NHS to do agency work or are at least doing it to supplement the wage they already earn.
This means that the NHS service is unable to fill empty nursing posts with full-time permanent staff.. and are having to take on more agency staff who are more expensive to make ends meet.
A vicious circle....