ROME — The construction of a high-speed rail link between Italy and France — an issue that threatened to splinter Italy’s governing coalition — survived a vote in Parliament on Wednesday. So did the coalition, though the nationalist League party came out clearly ahead of its governing partner, a weakened Five Star Movement.

“Those who vote ‘no’ are putting the government at risk,” Deputy Prime Minister Matteo Salvini, the interior minister and leader of the League, warned this week as he urged support for the 8.5-billion-euro infrastructure project connecting the Italian city of Turin with Lyon, France.

As is often the case these days, Mr. Salvini, whose base of voters in the country’s industrial north supports the project, came out the winner.

The vote on the project, known as the TAV, was nonbinding but politically meaningful.

The League has enthusiastically backed the TAV, citing jobs and other economic benefits it says the rail line will generate in the north. The Five Star Movement, which opposes the project, was founded in part on fighting the corruption and environmental damage it sees as endemic to large infrastructure projects.