http://www.publications.parliament.uk/pa/cm200506/cmselect/cmdfence/986/986we13.htm
A link to the house of commons defence commitee report on the matter.
Edit - removed my lengthy anti-nuke rantings as off-topic. But basically i'd think it's more likely we get nuked due to having to participate in a US strike, than us getting taken over by a foreign power if we didn't have them.
On-topic - I shall be voting monster-raving-looney or defacing my ballot as usual, until someone that isnt a douche or a turd is availible to vote for. I'd be interested to see the figures for gun-crime involving RIF in the UK and what the expected result of banning them is. If they became illegal there'll be thousands of illegal RIF floating around the country and many would sell them illegally rather than hand them in to be destroyed (if a paint job wasn't enough to stop it counting as RIF). So effectively it'd flood the criminal markets with RIF and increase the amount of crime commited using them.
Of course unless someone shoots you can't tell if it's real or not so very hard to judge how much RIF is used in crime.