On Wednesday Thurgau's parliament voted 68 to 53 in favour of a 2013 motion to abolish the teaching of French at primary school level.
The vote is the latest move in an ongoing saga related to the teaching of national languages in Swiss primary schools.
Thurgau is one of several cantons in the German-speaking part of the country which don't want to teach French at primary school, preferring pupils to learn English instead.
The move goes against a 2004 federal language teaching strategy and a later ‘harmonization' agreement, approved by the cantons and the people, which decreed that two languages should be taught at primary school, at least one of which should be a Swiss national language.
But citing lack of resources and time, some cantons including Thurgau are making plans to teach just one language, and say that one should be English.
Though education policy is generally set at cantonal level, the row was inflamed last year when the federal government said it would intervene if the cantons failed to prioritize national languages.
The question is an emotional and delicate one for multilingual Switzerland and has divided opinion. The Thurgau motion was supported by the Swiss People's Party, the Greens and the Christian-Democrats but opposed by the Liberal-Radicals, Socialists and centre parties.
Wednesday's vote is not definitive, however. A second round of voting will take place in June, and it's likely that if approved again in parliament it would be put to the Thurgau public in a cantonal referendum later in the year, Swiss media said on Thursday.
Reacting to Thurgau's vote MP Mathias Reynard said: “This decision is unacceptable and shows the arrogance in certain quarters towards French-speaking Switzerland and the minority languages of our country,” reported Le Temps.
The question is also being raised in other cantons.
On May 21st the people of Zurich will vote in a cantonal referendum on whether to teach just one foreign language at primary school rather than the required two.
If approved, it remains to be seen if that language would be French or English.
And now the canton of Graubünden is likely to go down the same route after Switzerland's highest court on Wednesday said the canton was allowed to hold a referendum on teaching one language at primary level rather than two.
If accepted by the people, the multilingual canton would teach only English at primary level in German-speaking areas, but only German in Italian and French-speaking regions.
Opponents to the proposed referendum said it would lead to discrimination on linguistic grounds, but a majority of Federal Court judges disagreed, reported news agencies.
Similar one-language referendums are likely in Lucerne and Basel-Country in the future, said Le Temps.
Though Thurgau has made headlines for several years on the matter, it is not in fact the first canton to abolish the teaching of French to primary school kids.
The famously conservative Appenzell Innerrhoden – Switzerland's least populated canton – dropped it in 2001 in favour of English.
Speaking to Le Temps the cantonal government's president Roland Inauen said it had been a positive experience.
“With an increase in French lessons at secondary level and excellent teachers, by the end of compulsory school our pupils reach a level of French that is as good as those from cantons where it is taught from primary school level,” he said.
But Le Temps points out that no scientific study has been conducted to confirm this.
As for Switzerland's third national language, last year Ticino's education minister complained that the country often “forgets” about Italian.
If the government wants to promote national languages then Italian should be offered in all schools, at least as an option, he said.