I think he favors keeping the pound sterling and staying out of the Euro. I do not think he favors withdrawal from the EU itself.
Agreed. I believe that line in the article may be in error, or perhaps oversimplified, as evidenced by this EU policy page from the Conservative Party
The Conservative Party - Policy - Where we stand - Europe
and also this page
The Conservative Party - News - News - A policy on Europe that people can believe in
Another page that may be of interest to us Yanks:
David Cameron Bio
The Conservative Party - People - David Cameron