This week around 3,000 blank British passports due to be sent to embassies around the world have been stolen from a van that was hijacked near Manchester, in what the Government admits was a major security breach.
It is claimed that these can not be used as they have security chips on them, however this article on the BBC website ePassports 'at risk' from cloning, 15 December 2006 explains how easy it was to clone one of these chips at the time. If you can make a copy of the data on the chip I'd say you were pretty close to being able to change that data and create a fake electronic passport. This would have been impossible at the time as you would have needed some blank passports to write to.
