AV won't save the Lib Dems or Clegg. Most Lib Dem MPs get less than 50% of the vote, under AV you need to get over or near 50%. Lib Dems are so unpopular at the moment, they will find it harder to win seats under AV. Vote YES to AV because it is fairer, but also if you want to help give Clegg a kicking!
Remember that nearly all MPs in safe seats oppose AV. I wonder why that is? They are funding full page ads to get you to vote NO, they must be really scared of losing their gravy train. Make them work harder for your support. Vote YES to AV on May 5th.
*INTERESTING UPDATE* I notice the Tories have just lost a council seat to the Lib Dems in true blue Tunbridge Wells of all places! The voteshares were as follows; LD 43%, TORY 34%, UKIP 23%. It is very likely that AV would have meant the Lib Dems not gaining the seat from the Tories because nearly all UKIP voters would have preferred the eurosceptic Tories to the pro-europe Lib Dems and the Cleggers would have failed to get 50% support.
This is how preposterous our present system, first-past-the-post is, if a party of the left had stood say Labour or the Greens, then the Tory would have held on, but because UKIP a right-wing party stood, the right wing Tories lost.