WELLINGTON, May 9 (Xinhua) -- Law changes to enable New Zealand to ratify the controversial 12-nation Trans-Pacific Partnership (TPP) trade deal have been tabled in the country's parliament, Trade Minister Todd McClay said on Monday.

The Trans-Pacific Partnership Agreement Amendment Bill would make all domestic legislative changes required to comply with New Zealand's obligations in the TPP, with the exception for obligations related to plant variety rights, which New Zealand had a three-year period following entry into force to implement, said McClay.

"Although most of the obligations in TPP can be met by New Zealand's existing domestic legal and policy regime, some changes are required," McClay said in a statement.

The legislative amendments introduced by the Bill would not come into effect until TPP entered into force for New Zealand.

"It is worth remembering that TPP is our biggest FTA (free trade agreement) to date, and places us centrally in a region encompassing nearly 40 percent of global GDP (gross domestic product)," he said.

However, the TPP is arguably one of the most divisive trade pacts New Zealand has ever entered into, with the three main opposition political parties committed to fighting it.

The government has accused the main opposition Labour Party of breaking the country's political "consensus" on free trade by opposing the deal.

At the weekend, McClay said the Labour Party's opposition "flies in the face of Labour's long history of welcoming free trade agreements."

Critics say the country will be effectively ceding sovereignty over a range of issues such as the environment, health and safety, and industrial relations, as the TPP's investor-state dispute settlement provisions allow corporations to sue governments over regulations that could affect their profits.

The TPP could come into force by late 2017 or early 2018, when the signature countries have completed their respective domestic processes necessary to ratify the agreement.