Here is an interesting post from the blog “Working Languages” about the EU’s shortage of qualified into-English interpreters. The EU blames the candidates’ poor English skills, characterized by overuse of the word “like,” while the blogger argues that a larger culprit is the lack of financial incentives for qualified interpreters.
Concernig the shortage of English interpreters I can give you the position of the translation agency Datawords(http://www.datawords-translation.co.uk) where I worked during a few years. At the time we had a lot of problems to find English interpreters and especially quality English interpreters.
I remember that it was an every day battle to get the best interpreters on our missions.
To achieve our goal we had to trust graduated but young and inexperienced interpreters.