David Cameron is arriving in Japan for a G7 summit at which he is hoping for further international backing for Britain to stay in the European Union.
But Brexit is not on the official agenda for the meeting of leaders of seven world powers - the UK, US, Japan, Germany, France, Italy and Canada - which is set to be dominated by the world economy, terrorism and threats to the steel industry worldwide.
As leaders of the UK, US, France, Germany, Italy and Canada were welcomed to coastal resort Ise-Shima, steel industry leaders combined to send a plea for action to tackle steel-dumping by China, whose over-production has sent prices tumbling around the globe.
A statement signed by steel trade groups from the US, Europe, Canada, Japan - and by UK Steel in Britain - warned that the current crisis will continue to put pressure on producers, with the potential for more plant closures without action to deal with the problem at source.
Gareth Stace, director of UK Steel said: "Chinese government policies have contributed to significant global excess capacity in steel, unfair trade and distortions in steel trade flows around the world.
"If the G7 leaders fail to address or halt market distortions it will mean subsidised and state-supported enterprises surviving at the expense of efficient companies operating in environments with minimal government support.
"That's why we are urging leaders at the summit in Japan to discuss the need to maintain effective remedial measures, consistent with their World Trade Organisation rights and obligations, against exports from countries in which market economy conditions do not prevail."
The annual G7 summit is the last gathering of world leaders Mr Cameron is scheduled to attend before the June 23 referendum on Britain's EU membership.
The referendum is certain to feature heavily in conversations in the margins of the event and the Prime Minister will be hoping for a united show of support for a Remain vote from host Shinzo Abe and his fellow leaders.
On a visit to London earlier this month, the Japanese PM warned Brexit would make the UK "less attractive" to investors from his country. And he said Japan would prefer to seal a free trade deal with the whole EU, rather than individual states.
Negotiations on the EU-Japan deal are high on the agenda for talks at the Ise-Shima coastal resort, with G7 leaders expected to back early completion of talks which began in 2013. Both Mr Abe and European Commission president Jean-Claude Juncker have said they hope the deal - which Downing Street believes could be worth £5 billion a year to the UK - can be sealed by the end of 2016.
But Mr Cameron is set to be at loggerheads with his host on broader economic policy, setting his face against Mr Abe's drive for a co-ordinated fiscal stimulus by G7 states to inject vigour into the lethargic global economy.
British officials said that Mr Cameron's priority will be to encourage the G7 to back "flexibility", with an approach permitting member states to pursue economic policies appropriate to their particular circumstances.
The PM will press for G7 condemnation of missile-testing in North Korea, and will seek support for the extension of sanctions against Russia when they come up for renewal in the summer. He will voice Britain's support for the extension into Libyan territorial waters of the EU's Operation Sophia mission against people-trafficking.
The final communique of the two-day summit is thought unlikely to give explicit G7 backing to the Remain side in the Brexit debate, but leaders including Mr Abe, US president Barack Obama and Canadian PM Justin Trudeau have already made clear their concerns about the negative consequences they expect from EU withdrawal.
A meeting of G7 finance ministers last week concluded that a potential UK exit would "complicate the global economic environment", while Germany's Wolfgang Schauble told reporters: "We were all of the opinion that it would be the wrong decision for the UK."
Britain is the only G7 country to honour a pledge to give 0.7% of its national wealth to the world's poorest people after the foreign aid budget soared by 144% in a decade.
The world leaders are meeting as the Daily Telegraph reports - citing a G7 survey - that the UK is spending nearly twice as much as other members of the club of major industrialised democracies.
Prime Minister David Cameron pledged to stick to the UN target of spending 0.7% of GDP on overseas development projects despite cuts in other areas.
The UK's aid budget increased to £13.2 billion in 2014 based on current exchange rates, according to a progress report issued as G7 leaders gathered in Japan.
The study shows that Germany and France give around 0.4% of GDP, while Canada gives less than 0.3%, and the US, Japan, and Italy give less than 0.2%.