A European Union regulation is brought into effect that provides for extensive paternity leave rights for employees in the public sector. The UK government, concerned over under-staffing of hospitals and increased waiting lists unsuccessfully argues against it in the Council of Ministers. Mindful of the direct effect of the regulation when it comes into force, the government secures the passage of a Bill restricting paternity leave rights for key medical personnel, including junior doctors, by allowing hospitals to insert clauses to this effect into contracts of employment. Tony, an overworked Irish doctor has his contract amended by the Borsetshire Health Trust and seeks to challenge the validity of the legislation on the basis that it conflicts with European law. Explain what arguments his Counsel would need to deploy in court and assess the prospects for success of these arguments.