EXPLAINED: Why do we need to wait till Thursday for Sweden's election result?

With mainly overseas votes left to count, the parties supporting Ulf Kristersson for PM have a one seat majority. How secure is their lead and could the Left bloc still clinch it?

EXPLAINED: Why do we need to wait till Thursday for Sweden's election result?
With mainly overseas votes left to count, the parties supporting Ulf Kristersson for PM have a one seat majority. How secure is their lead and could the Left bloc still clinch it?