can anyone explain to me how the shadow government is determined??

[flixx]

Is it just the party who comes '2nd in the elections? or is there more to it than that?

yes, I think its essentially that. The LibDems 'shadow' some positions (eg Vince Cable) but because of our warped voting system they don't have enough MPs to cover everything properly.

Well it's not so much that... there were 63 Lib Dem MPs in this most recent parliament.

The shadow cabinet is made up by the official Opposition... The Lib Dems aren't the opposition, they are the third party. They call their positions "shadow" eg "shadow chancellor" but the media for the most part disregards that and calls eg Vince "Treasury Spokesman"