There’s an early day motion calling for the VAT on compact fluorescent light bulbs (the energy-efficient ones) to the 5% level at which condoms are taxed (an interesting but apt parallel). Definitely a good one to lobby your MP on.
There’s also a petition, on which I haven’t quite made my mind up, to heavily tax the hideously inefficient (but cheap to buy) incandescent bulbs. Of course that makes environmental sense, but there could be some people left in the dark by inability to afford the efficient ones at some particularly point in time (even though they would of course save them money in the long run).