With its judgment No. 1350 of 26 January 2016, the Court of Cassation has held that a disciplinary sanction inflicted on an employee who, upon industrial unrest, had refused to substitute an absent colleague within a time frame outside normal working hours, regardless of an express obligation included in the trade-union agreement, is lawful. The commented ruling has thus laid stress on the need to identify an internal limit to the right to strike, outside which the refusal to fulfil part of the duties which may be lawfully requested by the employer constitutes a breach of contract on the employee’s side and not an anti-union conduct on the employer’s side.