This was drawn for a local paper this week. I notice that another cartoonist came up with basically the same joke in the current Private Eye. This kind of thing happens a lot with topical cartoons, it's inevitable when we're all thinking about the same subjects and working within the parameters of the gag cartoon.
Now, of course, we know who won, and I suspect that the resulting Conservative and Lib Dem coalition will be a gift for cartoonists.
Royston's portfolio website