Well you could, Mark, but it would be a bit hypocritical. Those that did not vote are entitled to the full services of their MP. You do not have to show “proof of voting” before you can approach him or her.
Although it has strayed a bit from the original question, this thread is interesting in that it displays some of thinking that surrounds democracy and voting in the UK:
“I don't think anyone voted for the present government”
Indeed they did not. The electorate never votes for a government or a Prime Minister in the UK, they vote solely to elect their own MP. The Queen invites one of them to take to post of Prime Minister and form a government. It is Party Politics (which has done more to devalue our system of democracy than anything else) that dictates who this should be.
“It is clear that the LibDems have agreed to Conservative plans...”
Yes indeed they have, and in return they have a quarter of the Cabinet posts – something that without a hung Parliament and their participation in a coalition they could never have dreamed of. In return the Conservatives (who gained by far largest number of votes and seats in the election) call most of the shots.
“...the LibDems have failed to get an agreement for the introduction of a proportional voting system.”
Partly true, but they have an agreement to a referendum on the AV system – something which neither of the two main parties would have acquiesced to (unless you believe Labour’s “death bed conversion” in the days following the election). Voters need also to understand that should this, or any form of PR be introduced, a “hung Parliament” (where effectively everybody gets what nobody wants) will become the norm.