According to this new article from The Register, the C and PHP languages will no longer be taught as a part of the A-Levels computer science course materials.

A-level computer science students will no longer be taught C, C# or PHP from next year following a decision to withdraw the languages by the largest exam board. Schools teaching the Assessment and Qualifications Alliance's (AQA) COMP1 syllabus have been asked to use one of its other approved languages - Java, Pascal/Delphi, Python 2.6, Python 3.1, Visual Basic 6 and VB.Net 2008. The final resits allowing work in C, C# and PHP will be held in June 2011.

According to this document and the AQA, the change is a response to the lack of momentum of some of the other approved languages. They say that the demand for teachers trained with the languages has made PHP and C fall by the wayside to be replaced with things like Delphi or Python.