The NGO Oxfam has been scathing about the process under which Tonga is joining the World Trade Organisation describing it as hypocritical and political.
Tonga will become the WTO's 151st member next month after 10 years of negotiations.
The ratification was deposited with the Geneva-based WTO yesterday and automatically becomes effective a month later.
But Oxfam's Barry Coates says Tonga is getting a bad deal and he is disappointed that the country has agreed to such a package.
"It's a very, very tough that Tonga's got and we're frankly quite angry that the rich countries have required Tonga to do what its been required to do to join the WTO. It's a very unfair process where Tonga has been forced to take on obligations that other countries that are currently members of the World Trade Organisation don't have to take on."