PARIS — Anti-racism groups joined French unions and a brand-new left-wing coalition in protests in Paris and across France on Saturday against the surging nationalist far right as frenzied campaigning is underway ahead of snap parliamentary elections.

The French Interior Ministry said 250,000 people turned out to protest, 75,000 of them in Paris. Despite rainy and windy weather, those who fear that the elections will produce France’s first far-right government since World War II gathered…