I received a reply from my host regarding the problem. This is what they said:
It looks like the wp-config file is setup incorrectly and is trying to pull up your content from a mysql database called, wrdp1
This database doesn’t exist which is why you are having this issue. Do you know which database the site is supposed to pull up from?
if you can reply to this email with the correct database we will be more than happy to link your wordpress with the correct site.
As far as I can see there appear to be two points in the config.php file that access the database (username and password lines). They are both accessing the correct database name.
What is the name of the database the config file needs to be accessing?