John Key arrives at G20 summit

John Key and wife Bronagh arrive for the G20 and are met by Queensland Deputy Premier Jeff Seeney and Australia's associate minister of defence Stuart Robert (right).

When Prime Minister John Key arrived in Brisbane this morning he walked into the fug of 35 degree heat and an atmosphere of pure concentrated political power.

New Zealand is a 'guest' at the G20 - a summit of the leaders from the 20th richest, most powerful countries in the world. Key has described it as a chance in a life time.

For New Zealand, the real opportunities dwell on the sidelines. Having already spoken to many of the leaders over the past week at Apec and the East Asia Summit, Mr Key will be making the most of the chance to sound out European leaders. That is particularly so after German Chancellor Angela Merkel's stronger than expected expression of support for an EU - NZ free trade agreement in Auckland yesterday.

Key will not want to waste the chance to use that to build momentum. Trade Minister Tim Groser will also be at the G20 to make the most of that.

The international issues currently at play also guarantees Key will not simply a wallflower at the G20 Summit, given New Zealand's election to the Security Council.

The fractiousness in international affairs will mean leaders talk about Islamic State.

Russia is another hot topic and is showing its muscle by dispatching warships toward Australia as it faces international condemnation and concern over the Ukraine.

All those issues will dominate headlines from the sidelines. The major development of a climate change agreement between the United States and China will also be a hot topic - putting pressure on other countries to follow suit.

However, the G20 is predominantly an economic forum. It can be pretty dry stuff - hence the media focus on the length of the motorcades the Big Three (Obama, Putin and Xi) have flown in for the occasion, the security measures locking down Brisbane and protests.

Mr Key and German Chancellor Angela Merkel both pointed out those international issues had economic ramifications.

Mr Key said if there was a worsening of the situation with Islamic State or in Russia and Ukraine it could result in a further slowdown in Europe and that would be bad news for all.

"We are already seeing some slowdown there and given the size of the European economy we all need Europe to be a powerful growing economy again. That is the challenge for G20 and the growth pathway for next 12 to 24 months.

New Zealand has had some kudos internationally for withstanding the global financial crisis without resorting to austerity measures and quantitative easing. The theme of the summit is ensuring economic growth in the wake of that crisis and building resilience to future shocks.

Key will be one of the longest serving leaders at the meeting. Other than Russian President Vladimir Putin's previous roles, only four other leaders have been in office longer than he: Argentina's President Cristina Fernandez de Kirchner (2007), German Chancellor Angela Merkel (2005), Canada's Prime Minister Stephen Harper (2006) and Singapore's Prime Minister Lee Hsien Loong (2004).

Key made it clear he will be pushing the case for free trade as a way for that to happen, saying he believed free trade was a key feature in ensuring sustained economic growth.

He said that was also why US president Barack Obama was prioritising the Trans Pacific Partnership and China was looking at its own regional arrangements.

He said the world would also have to adjust to a post-quantitive easing environment.

The G20 also provides Key with a chance to get in some pre-emptive work before New Zealand takes its seat on the Security Council in January. NZ stood on a platform of reform of the Security Council, in particular the veto powers of the P-5 which have often rendered the Council impotent.

Any reform will require political good will from the P-5 - and all five leaders are at the summit providing Key with the chance to get in their ears. Of them only France has so far indicated any willingness for reform - and Key will be staying at the same hotel as French President Francois Hollande.

Key will have some backing from heavyweights such as Brazil's Dilma Rousseff. Brazil is also calling for the changed world to be reflected in the makeup of the Security Council which has stuck with its post World War II structure despite the shifting the shifting power bases since.

Who will be at the G20?

• Australia Prime Minister Tony Abbott
• Argentine President Cristina Fernandez de Kirchner
• USA President Barack Obama
• South Africa President Jacob Zuma
• Brazil President Dilma Rousseff
• Russian President Vladimir Putin
• French President Francois Hollande
• Mexico President Enrique Pena Nieto
• Korea President Park Geun-hye
• China President Xi Jinping
• Indonesia President Joko Widodo
• Saudi Arabia Crown Prince Salman bin Abdulaziz
• German Chancellor Angela Merkel
• Canada PM Stephen Harper
• UK PM David Cameron
• Japan PM Shinzo Abe
• Italy President Matteo Renzi
• India PM Narendra Modi
• Turkey Prime Minister Ahmet Davutoglu.

The European Union will be represented by European Council president Herman van Rompuy and European Commission president Jean-Claude Juncker.

Invited guest countries are New Zealand, Singapore (PM Lee Hsien Loong), Spain (President Mariano Rajoy Brey). The African Union will be represented by Mauritania President Mohamed Ould Abdel Aziz, ASEAN by Myanmar President U Thein Sein and NEPAD by Senagal President Macky Sall.

Groups represented include the United Nations, International Labour Organization, World Bank, International Monetary Fund, OECD, World Trade Organization, and Financial Stability Board.