Lead by former Howard Minister the Hon. Peter Reith, Cornerstones team includes some of the most respected names in Australian public life. Our broad experience of the both politics and business as well as our deep understanding of how government works makes our team one of the most respected and capable in the nation.

Joseph Tannous


Joseph is the founder and Executive Director of the Cornerstone Group having had an extensive background in advocacy, government relations and public policy making.
Joseph's experience in the workings of government, politics and communications span a 25 year involvement with the Liberal Party, campaigning and advising on political strategy and representing the community. Joseph was elected to council in 1999 and later as Mayor in 2001.
Joseph has managed major political and grass-roots campaigns throughout Sydney, attaining election winning results at local, state and Federal elections. He has developed a natural instinct for political organisation and planning, involving a close association with many State and Federal Party leaders.
Joseph's range of current contacts, his political antenna and business knowledge continues to greatly aid the organisations he advocates on behalf of moving them confidently into dealing more ably with government.  
His knowledge of the ever-evolving nature of politics and of the necessity for effective communication between business and government enables him to take a leading advocacy role and provide top-level strategic advice.


The Hon Dr Peter Hendy


Peter joined Cornerstone Group as a Non-Executive Director following his role as Chief Economist to the Prime Minister, the Hon Malcom Turnbull MP. Prior to that he was the Assistant Minister for Finance, Assistant Cabinet Secretary and Assistant Minister for Productivity in the Federal Government and the Member for Eden-Monaro in the Federal Parliament between 2013 and 2016.

He has an extensive background in both the corporate and public sectors, having been a member on the boards of Standards Australia, the Australian Institute of International Affairs, the Australian Made campaign and the National Institute of Labour Studies. He has also been a member of a number of committees in the OECD including International Chamber of Commerce, Confederation of Asia-Pacific Chambers of Commerce and Industry and spent almost six years as the Chief Executive Officer of the Australian Chamber of Commerce and Industry.

Prior to that Peter was Executive Director at the Bahrain Economic Development Board in the Middle East, Chief of Staff of the Minister for Defence; the Federal Minister for Employment, Workplace Relations and Small Business; and the Federal Minister for Education, Science and Training. He has also been Chief of Staff to the Leader of the Federal Opposition.

In 2003, he was awarded a Centenary Medal by the Governor General for service to Australian society in business leadership. Peter is a Fellow of the Australian Institute of Management and a Member of the Australian Institute of Company Directors.

Dr. John Tierney OAM, PHD


A government relations authority, John has worked at the state and federal level with a wide range of corporate clients for over a decade. His extensive experience spans some of the major industries facing reform, including; construction, power generation, mining, agribusiness, pharmaceuticals, finance, information technology, telecommunications and defence. 

For fourteen years John gave distinguished service to the Australian Parliament serving as a Senator for NSW. During this time John was a Shadow Parliamentary Secretary and chaired numerous Senate Standing and Select Committees particularly focused on the Education, Employment, IR, Communications, Health and Transport portfolios. John has also led Australian Parliamentary Delegations to South Africa, Nigeria, the European Union and the United Nations in New York.

Dr. Tierney has served on the Council of the ANU, as a Senior Lecturer at the University of Newcastle, on the Council of the National Library of Australia, as national patron of Lifeline Australia and national patron of Polio Australia. 


Mitch Tanner MA BCom


With a diverse background across the public and private sectors, Mitch brings a wealth of experience to Cornerstone Group.

Most recently, Mitch worked for a senior federal Cabinet minister, advising on a wide array of portfolios; including: Treasury, Finance, Foreign Affairs and Trade, Industry, Innovation and Science, Infrastructure and Transport, Agriculture and Water Resources, Social Services, Resources and Energy and Environment.

Mitch has also worked for two Speakers of the Parliament, where he developed a high-level knowledge of parliamentary procedure. Prior to this, Mitch worked for an ASX200 company.

For almost a decade Mitch has worked on a number of federal and state marginal seat campaigns across New South Wales, Victoria, and Queensland.

Mitch has a Bachelor of Commerce (Economics) from the University of Melbourne, a Master of Arts (International Relations) from the Australian National University, and is currently studying law at the University of Sydney.

Brigid Meney BA MN RN


With a strong policy background across a range of core fields of government, Brigid comes with expertise as both a political adviser and a departmental professional.

Having worked for a number of years as a Senior Adviser in Canberra, Brigid brings an extensive knowledge of the national political landscape and the policy procedures of government.

More specifically, Brigid brings a keen understanding of the state and national health systems with a range of contacts and knowledge brought about by experience both as a qualified health professional followed by her service as a Health Adviser.

With a desire to return home to Sydney, Brigid left the capital to serve in the Department of Premier and Cabinet, working as part of the Local Government Reform Taskforce dealing with the live issue of council amalgamations across NSW.

From grassroots election campaigns in some of Australia's most marginal seats, to her participation in Australian delegations to the United Nations, Brigid brings a passion for all tiers of government spanning her entire professional life.


Dermot (Derry) Horgan


Derry Horgan is the resident tender specialist on the Cornerstone team. He has had a long career in selling to Corporations and Government agencies both in Australia and New Zealand having specialised in developing internal and external strategies for effective tendering and at the same time building strong relationships with a wide range of stakeholders, particularly in the Federal and State public services.

His experience working on senior executive teams in a variety of organisations includes developing growth plans, building governance cultures, monitoring performance and ensuring compliance. 

He has a depth of understanding the process of selling to Government; from the pre tender stage through to tender preparation, contract negotiation and contract implementation. Derry's knowledge of procurement and sales (including B2B integration) coupled with his connections in Government in Australia and New Zealand makes him an extraordinary asset to anyone who is seriously looking at selling to Government agencies in either of these countries.

Rosie Garzaniti BCOM


Rosie joined the Cornerstone team in 2016 after having previously worked in the corporate, retail and hospitality industries. Rosie spent over 8 years at Bankers Trust and worked in a variety of marketing and client liaison roles as a member of the BT Client Relations and the Funds Management- Institutional Business Development team. As a small business owner and manager of Ntice at Chifley Corporate Catering, Rosie has gained extensive experience in areas of marketing, business development, event management, communications, administration and stakeholder engagement. 
Rosie was formally educated at Santa Sabina College, Strathfield, has a Bachelor of Commerce (Economics & Finance) from University of Western Sydney and a Diploma in Marketing from the Australian Professional Marketing Institute



Stephanie Tannous


The Cornerstone Groups dedicated research staff develop and prepare detailed briefs on policy and legislation for our clients. Their research is used to construct comprehensive government relations programs which are tailored to clients' needs as well as being sympathetic to the policy drivers of decision makers.

The Cornerstone Groups research staff also monitor all major media outlets to make sure our clients are up to date on issues discussed in the fourth estate. Additionally, they manage our program of prominent networking events and help the senior team to develop and implement government relations, policy and campaign strategies.