Let's say that in 1992, the Conservatives lost their overall majority in the Commons, but kept the largest number of seats to form a Minority Government, after coalition talks failed. During the Summer, the Government is very shaky, and on Black Wednesday (16 Sep), support for the government's economic policies totally collapse.
A rejuvenated Labour Party is able to win a Motion of No Confidence, with support from most of the other parties (and a few Conservatives). Therefor, Parliament is dissolved, and new elections are set for October, just six months after the previous ones.
How would the election play out?