MANTLE - Key Persons


Anton Ashcroft

Passionate about fostering great leaders, Anton has many years of experience facilitating both individuals and groups through the process of change, personal development and conflict resolution. With a tertiary qualification in psychology, one of his unique strengths is his ability to take complex ideas, such as the neuroscience principles that underpin our approach, and turn them into practical tools and techniques.

Denise Carter - Founder

Job Titles:
  • Co - Founder
Co-founder, Denise has more than 30 years' experience in leading and developing people. Her career has seen her in roles ranging from an Officer in the armed forces, to senior group learning and development positions in some of the UK and New Zealand's largest organisations. Her focus on relationships supports long-term partnerships with our clients, some of whom have been with us since we started.

Graham Hart

Job Titles:
  • Founding Director of the Business, Graham
A founding Director of the business, Graham has more than twenty-five years' experience working in operations, human resources and management consulting roles. His relentless curiosity and creativity are two of the main reasons Mantle continues to grow its impact on the leadership world.

Jon Dunning

Job Titles:
  • People Leader
Jon is an experienced people leader, facilitator and coach. Whether in a small team environment or a large, complex and diverse organisation, Jon looks for opportunities to translate the strategic into operational in order to meet our clients' ultimate goals. His focus on developing sound partnerships with our clients is a key factor in the sustainable outcomes they achieve.

Kimble Vowless

Kimble has been involved in learning and leadership development for over 20 years. He recently led the capability and development team in one of NZ's most prominent private corporate organisations for seven years and was involved in large-scale development projects. An experienced and confident learning designer, facilitator and coach at all leadership levels and using different modes of delivery

Lettie Dalton

A highly experienced, commercially astute and passionate facilitator, coach and trainer, Lettie has a proven background in working with corporate organisations worldwide to empower, motivate and engage people. Lettie loves to experiment, operating within the learner's context and gently pushing them to try new things in order to gain fresh insights.

Mark Wirihana

Mark is a warm relationship builder and a very effective facilitator and designer. Throughout his life, he has been involved in Tikanga Maori and has been influenced by the initial Kingitanga to modern Maori leaders (Ngata, Carroll, Ratana and TePuea Herangi). Passionate about building bridges between cultures and encouraging broader perspectives Mark is forever developing new skills and capabilities.

Nikki Hommes

Nikki has a Masters of Business Administration (MBA) Degree in coaching and mentoring and is a qualified life, executive and workplace coach. In addition to being an NLP Practitioner, she is a Master TetraMap facilitator, Talent Dynamic Flow Consultant & Ignition! Youth Coach. Enthusiastic and energetic, Nikki's passion for learning translates to highly motivating and encouraging environments.

Rachael Thomas

Rachael is passionate about helping others to connect, learn and grow at a time when the digital learning and meeting space has never been more important. Rachael is a coach and facilitator and brings over 16 years of leadership experience from her time in the aviation world. She provides learner support and virtual coaching to help learners get the most out of their learning experience.

Roxy Pringle

Roxy is the administrative guru for the Mantle team, providing day to day backup for the Directorship. She has a BA in Sociology and Criminology, and a varied background in administration, bookkeeping and events management giving her a vast range of skills and knowledge to impart. Give it to Roxy and it gets done!

Ruth Donde

Ruth is part of the Mantle leadership team and is the Director responsible for driving the amazing standards of delivery we are known for. She is passionate about leadership development, and the impact of personal and professional development on individuals, relationships and organisational outcomes. Her commitment to continuous learning is also applied to ensuring our own team's capabilities are constantly evolving.

Saskia Clements

Saskia is passionate about unlocking potential in individuals and organisations. She is a highly respected facilitator, coach, and mentor. Saskia's positive and empathetic style allows her to challenge and encourage learners to harness insights and reach new levels of performance.