Italy's messy post-election drama on Sunday night took another stunning turn.

The country's president rejected a proposed populist 5Star-League alliance that included a Euroskeptic as economy minister and looked poised to appoint a "technocratic" government as early as Monday.

The collapse of the proposed coalition leaves Italy on an uncertain path in the days ahead, veering between the possibility of early elections or a technocratic government of longer duration. It also threatens a constitutional crisis, as the leaders of the 5Stars Movement and the League condemned the president and one even called for his impeachment.

Oh, and the most important: And it's sure to further rattle already nervous international financial markets.