Goals to wipe out extreme poverty drawn up under a panel led by David Cameron are set to be missed, a leading charity has warned.
The 2030 target will not be met unless rapid action is taken to tackle inequality, leaving an extra 200 million people unnecessarily living on less than 80 pence a day, according to Oxfam.
It is calling for global measures, including tax reforms, living wages and investment in public healthcare and education, to help make the plan a reality.
The call comes ahead of a meeting of the United Nations in New York where world leaders are expected to sign off on the pledge, which follow the Prime Minister's co-chairmanship of a high-level panel on new global development goals.
Oxfam used projections by World Bank economists that warn an extra 200 million people will remain trapped in extreme poverty by 2030 unless poor people's incomes grow faster than those of the rich.
Policy and campaigns director Francoise Vanni said: "The end of extreme poverty is within reach - in 15 years we could live in a world where everyone has the basics they need to get by and care for their families. But this won't happen unless we act to reduce rising inequality that condemns millions of vulnerable women, men and children to lives that are much tougher and shorter than they could be.
"World leaders face an historic challenge. They know that wealth does not automatically trickle down, so to deliver these goals leaders need to challenge the vested interests that are widening the divide between the richest and those most in need."
In its Inequality and the End of Extreme Poverty report, the charity said if the income of the bottom 40% of populations in developing countries had grown by two percentage points faster than the average between 1990 and 2010, worldwide poverty rates could have been as low as 5.6%.
That would allowed an extra 700 million people to have escaped extreme poverty over the two decade period.
Ms Vanni added: "We've halved poverty in 15 years but we could have done even better. If world leaders are now to keep their promise to end extreme poverty for good in the next 15 it's essential that they tackle inequality."