John Hayes

About the Lawyer

John Hayes is a leading employment lawyer in London and the founder of Constantine Law. He specializes in advising UK corporates across various sectors, including financial services, employment agencies, retail, and construction. His approach is solutions-oriented and commercially focused, making him a trusted advisor for businesses seeking employment law guidance.

In addition to his role at Constantine Law, John's entrepreneurial client base and experience in the employment sector motivated him to establish the firm in 2015. Prior to founding Constantine Law, he headed the London employment team of a large national law firm. John is a member of the Employment Lawyers Association, the Irish International Business Network (IIBN), and the Institute of Directors (IOD). He is also active in media and trade publications on employment law topics.

Experience

John has a distinguished career in employment law, having qualified as a barrister in 1993 and as a solicitor in 2001. He is a skilled advocate with extensive experience litigating in employment tribunals and the Employment Appeal Tribunal, handling cases related to unfair dismissal, whistleblowing, and equal opportunities. John is also highly experienced in High Court practice, particularly in restrictive covenant disputes, where he has successfully obtained numerous injunctions for leading corporate clients.

His client base is entrepreneurial and he regularly advises senior executives and owner-managed businesses. John has been instrumental in building Constantine Law into a leading employment law firm in London, with a focus on delivering commercial, solutions-oriented advice to middle market employers.

Specialty

John's legal expertise is primarily in labour and employment law with an emphasis on business protection. He works closely with leading barristers to safeguard his clients' commercial interests. His specializations include consultancy agreements, IR35, CIS, and the associated tax implications. He collaborates with accountants to deliver integrated legal and financial solutions.

John is recognized particularly for his work in restrictive covenant disputes and large-scale employment status matters, representing notable employers such as major employment agencies. His practice covers defending whistleblowing claims and advising on atypical working arrangements.

Education

John qualified as a barrister in 1993 and later as a solicitor in 2001. Specific details regarding his degrees or the universities he attended are not publicly available.

• Firm Ranking: Constantine Law, founded by John Hayes, is ranked in the Legal 500 for its employment law practice, highlighting the firm's recognized standing in the legal industry.
• Leadership Role: John Hayes is the Managing Partner and founder of Constantine Law, demonstrating his leadership and entrepreneurial role within the firm.
• Major Case Successes: John Hayes is noted as a leading solicitor in restrictive covenant disputes and an experienced High Court practitioner who has obtained numerous injunctions for leading corporate clients in the High Court.
• Professional Memberships and Contributions: John Hayes is a member of the American Bar Association, the Employment Lawyers Association, the Irish International Business Network (IIBN), and the Institute of Directors (IOD). He regularly appears on news media and contributes to leading trade magazines on employment matters.