Just days before some of the world's most powerful countries converge in Germany for the G7 summit, a new WikiLeaks document dump exposes secret negotiations that could further hamper US efforts to get its Congress on board with a pending trade deal.

The 17-pages outline the so-called Trade In Services Agreement or TISA. According to the documents, TISA covers air traffic, e-commerce and maritime trade among other things and involves the European Union, the United States as well as other countries like Canada, Australia, Pakistan and Israel.

Critics argue it would further consolidate corporate power in the hands of a few companies.

This comes at a sensitive time in trade negotiations in the US. US President Barack Obama has been urging Congress to pass a fast-track bill that would give him the authority to push through negotiations on the Trans-Pacific Partnership (TPP).

The TPP, which covers 12 countries including the US, has been in the works for years but has stalled because of opposition within the US and in TPP countries.

The deal has been criticised for its lack of human rights, environmental and labour protections. But it has also been criticised for the secrecy under which negotiations took place - the same secrecy that now allegedly covers the TISA discussions.

Members of President Obama’s own party in Congress are fighting him on the deal and are staunchly opposed to giving him any authority until changes are made to it.

The US is also in discussions with European allies over the Transatlantic Trade and Investment Partnership (T-TIP).

According to WikiLeaks, TISA would complete an alleged "trinity" that includes TPP and T-TIP and is a counter to countries like China, Russia and India who are developing their own agreements.

Critics are calling the WikiLeaks revelations nothing short of scandalous.

"Even my four-year-old can understand what's wrong with TISA," says Evan Greer, campaign director of Fight for the Future, a leading critic of the deal.

"When rules are made in secret without public discussion, they are never fair."