A record number of countries are expected to back a UN General Assembly call for a moratorium on capital punishment on Thursday, diplomats said.
The vote held every two years now sees the likes of the United States, Japan, China, Iran and Iraq stuck in a shrinking minority as pressure grows for an end to executions.
About 150 countries now have at least a moratorium on capital punishment and just 21 were reported to have carried out executions in 2011, according to rights groups.
European nations have pressed hard for votes backing a moratorium at the UN vote. Norway's ambassador Geir Pedersen said there could be 112 or 113 countries in favor this year, up from 107 in 2010.
But Pedersen said the growing numbers supporting a moratorium show "this is no longer dominated by western countries. This is a global campaign".
"The importance of the vote is that it sends a very strong message to the international community across the board," Pedersen told AFP. "The General Assembly is the one place where all nations are represented and you have a strong majority in favour of a moratorium."
"There is a global trend toward fewer countries executing people and for us, it is an important issue of principle," the ambassador added.
Pedersen said that when he raises objections to the death penalty in bilateral talks, "we have the feeling that they are on the defensive".
Rights groups say the remaining countries that carry out executions remain hardcore.
China executes thousands of prisoners a year, rights groups say, and Iran put to death more than 650 people in 2011, making it the highest per capita executioner.
Some countries defended maintaining their capital punishment at a UN committee meeting last month where 110 countries voted for a moratorium. Japan said it had to keep the possibility of hanging prisoners because "heinous" crimes are still being committed.
And the vote will be held the day after UN Human Rights Commissioner Navi Pillay called on Iraq to move toward abolishing the death penalty.
Iraq executed 70 people in the first six months of this year, compared to 67 for the whole of 2011, and 18 in 2010, according to the UN mission in the country.
"The number of executions so far in 2012, and the manner in which they have been carried out in large batches, is extremely dangerous, cannot be justified, and risks seriously undermining the partial and tentative progress on rule of law in Iraq," Pillay said.
The General Assembly will also have votes Thursday on human rights in Syria, Iran and North Korea where western nations hope that big majorities will put increased political pressure on the governments.
"It is an important message for some key countries to understand that there is a majority in the international community that wants to do the right thing on difficult issues," Pedersen said.