Undoubtedly politics come into the equation in here and Nearholmer has adequately summarised a framework for it. Most people aren't particularly partisan and the criticisms would be levelled at whoever the government was at that point in time. None of us know where the leader of the opposition contracted it from; his local pub, one of the many palace of Westminster bars, a member from the opposite benches (they do talk) etc?
I've had people accuse me of political bias through these topics - just for the record I have never voted Labour but there are some within that party that I respect immensely and there are decisions made by the government (that I didn't vote for last time) that I vehemently disagree with. I'm centrist and with an interest in what a candidate can do for a constituency as much as they can whilst having voting powers. Across all parties I respect conviction politics and do not like political opportunism, whatever the colour.