My employer wants me to work six days a week without extra pay

Under the Employment and Industrial Relations Act, Chapter 452 of the Laws of Malta, and the related Organisation of Working Time Regulations, employees are generally entitled to compensation for hours worked beyond what is specified in their contract, and requiring extra working days without additional pay, when your contract specifies a five-day week, is likely a breach of your contractual and statutory rights, regardless of how the employer frames it as temporary. You are also entitled under the working time regulations to adequate rest periods between working days and a minimum weekly rest period, and consistently working six days without proper compensation or rest may also raise separate working time compliance issues. Start by raising the matter formally in writing with your employer, referencing your contracted days and requesting either a return to your contracted schedule or proper additional pay for the extra day worked. If this is not resolved, you can file a complaint with the Department of Industrial and Employment Relations, which investigates breaches of employment conditions, or bring the matter before the Industrial Tribunal.