A coalition of US unions and advocacy groups has filed a lawsuit in federal court seeking to overturn new government rules that would restrict how long foreign students and journalists can remain in the United States. The regulations, set to take effect on 15 September, would cap student and cultural exchange visas (currently valid for the duration of a programme) at four years, while journalist visas would be limited to 240 days — or just 90 days for Chinese nationals. The plaintiffs, who filed their case in the US District Court for the District of Massachusetts, warned the changes would be "catastrophic" for universities and could cost the US economy billions of dollars by deterring international students, who represent one of the country's leading export sectors.