BERLIN (AP) — Germany's highest court said Wednesday it has thrown out complaints against a ban on the use of subcontractors in slaughterhouses that was prompted by coronavirus outbreaks early in the pandemic.

The Federal Constitutional Court said it rejected complaints by a sausage manufacturer and several temporary employment agencies against the new rules, which went into force at the beginning of last year.

They require companies to use their own work force to slaughter animals and process meat, with temporary work being restricted and phased out over a three-year period and exceptions only for companies with up to 49 employees.

The use of subcontractors, which was common in the German meat industry, often involved migrant workers living in cramped communal housing and being transported to slaughterhouses in minibuses — heightening the risk of infection when the COVID-19 pandemic hit. A major slaughterhouse outbreak prompted a regional lockdown in western Germany in mid-2020.

The federal court said the sausage company complained of inequality of treatment with other industries, while the employment agencies argued that the new rules violated their right to professional freedom. It said it rejected their cases because of a lack of sufficiently substantiated reasoning.