ROME — If at first, or second, you don’t succeed, try, try, try again. That was the lesson from Italy’s populist parties on Wednesday. After the collapse of their attempt to form a government earlier this week, they were back at the drawing board, and on the campaign trail, giving it another go.

The fact that President Sergio Mattarella had vetoed their euroskeptic choice for a key cabinet position, and that global markets sank with fears about instability in the European Union’s fourth largest economy, was apparently no deterrent for the populist Five Star Movement and League party.

Nor was the fact that Mr. Mattarella had only days ago called on Carlo Cottarelli, a former International Monetary Fund official and spending hawk, to form a technical government to guide Italy to a new election.

Mr. Cottarelli, who is unlikely to win a confidence vote in Parliament, had informal morning and afternoon meetings with Mr. Mattarella in the Quirinal Palace. But instead of presenting a list of cabinet picks, he apparently decided to hold off to see if the parties that won a majority of the votes in elections in March could find a way out of their impasse, according to the Italian news agency ANSA late Tuesday night.