The convention is that the first reading of a private members bill is passed without a vote or a debate. The reason for this is that there is not much Parliamentary time allocated to private members bills at all, so anything that speeds up a stage will be a good thing. However, anyone can object and force it to be debated - even at the first reading stage. That's what Chope and his buddies do. Then time must be found for a debate - which often never happens because Parliament never has enough time to cover off everything that it gets asked to cover. So, most private members bills do not make it into law as they are at the back of the queue when it comes to being scheduled, run out of time and get scrapped.
The up-skirting furore was such bad publicity for the Conservatives that the private members bill proposal was adopted by the government. Therefore, no longer a private members amendment but a government one - which is higher up the pecking order and gets more debating time. No idea if it's law or not yet.
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