Byrne Wallace Shields, formed by the merger of Byrne Wallace LLP and LK Shields Solicitors, stands out for its portfolio of private, semi-state and public sector clients. It is widely recognised for its history of acting in public sector disputes, including representing state and public agencies in the health, educational, property and tourism sectors. The firm frequently advises public and semi-public bodies on internal investigations and continues to build its presence in cybersecurity and data breach matters. The newly expanded offering is also rated for insurance cases, regulatory litigation and landlord and tenant disputes, and is building its standing in shareholder cases and cross-border disputes. Jon Legorburu heads the disputes and investigations department, and is an experienced figure in public sector cases, regulatory investigations and white-collar crime. Mona Costelloe is also noted for public law cases, real estate disputes and regulatory enforcement, Jill Callanan continues to stand out for shareholder disputes, commercial contract cases and property matters, and Ian Lavelle specialises in insurance and construction disputes. Sean O’DonnellValerie Hourigan Mark O’Shaughnessy and Clare Dowling are also key partners.

Legal 500 Editorial commentary

Testimonials

Collated independently by Legal 500 research team.

  • ‘The team is very responsive on all matters. They have wide ranging expertise, which they can bring in as required. They are dependable, reliable and advice received is generally well grounded.’

  • ‘Mona Costello and Seán O’Donnell particularly stand out. They have provided an excellent service to us throughout the management of follow up actions arising from a cyber attack. They have been reliable, consistent and very professional in all their dealings.’

  • ‘Mark O’Shaughnessy and ByrneWallace provided a level of expertise and strategic insight that was crucial in managing the situation effectively. Their ability to handle these complex legal issues with professionalism and composure made them a standout choice in resolving the matter efficiently.'

  • 'From the outset, Mark O'Shaughnessy and his team demonstrated exceptional professionalism, knowledge and a reassuring demeanor. Their approach instilled confidence and provided a clear path forward despite the challenging circumstances. Mark's ability to navigate the complexities of the situation was evident. His game plan and strategic thought process was well-crafted and executed, showcasing deep expertise and innovative problem-solving skills.'
  • ‘BW were diligent, committed and professional. They also demonstrated a most welcome willingness to challenge me as and when it was required. Explanations of decision trees, candour and risk return analysis were specifically appreciated. I always felt that advice was a call away and that I understood the advice, the context and risk.’

  • ‘Very responsive and user friendly across a range of sectors.’
  • ‘Jennifer Clarke is a standout adviser. She makes complex issues clear and is very commercially focused.’

Key clients

  • Parcel Connect t/a Fastway Couriers
  • Association of Secondary Teachers, Ireland
  • Residential Tenancies Board
  • Health Service Executive
  • Inland Fisheries Ireland
  • Ballymore Group/Ballymore Residential
  • Department of Justice
  • An Bord Pleanála
  • National Treatment Purchase Fund Board
  • The Medical Council
  • Declan Taite and Sharon Barrett of Kroll Advisory (Joint Receivers of Janel Investments)
  • Veon Limited, Trevor McHugh, Paul Brosnan (former Directors of the Irish Forestry Fund Companies) IFS Forestry Services
  • Fidelis UK
  • Chevron Global
  • Aengus Burns of Grant Thornton
  • Kaleyra UK Limited
  • Coface US and Coface UK
  • Annaba ULC
  • Executive Authority for Special Flights

Work highlights

  • Advised and successfully acted on behalf of the National State Health Agency in commercial proceedings before the High Court and appeal to the Court of Appeal in respect of a dispute with a private hospital provider.
  • Acted for Ballymore Group/Ballymore Residential in a long running High Court litigation against CRH and its subsidiary Roadstone.
  • Acted for the Department of Justice, through the Supreme Court, to challenge the constitutionality of the Judicial Appointments Commissions Bill 2023.

Practice head

The lawyer(s) leading their teams.

Jon Legorburu

Other key lawyers

Mona Costelloe, Jill Callanan, Ian Lavelle, Seán O’Donnell, Valerie Hourigan, Mark O’Shaughnessy, Helen Gibbons, Clare Dowling, Eamon Jones, Shane Neville, Jennifer Clarke