THE Gillard government has accused tobacco giant Philip Morris of engaging in corporate restructuring as a ''trick'' to find new legal avenues to challenge plain cigarette packaging laws.

The company has launched a multibillion-dollar compensation claim against the government through its Hong Kong arm, Philip Morris Asia, claiming the packaging laws breach a trade treaty between Hong Kong and Australia.

Philip Morris says the plain packaging laws will adversely affect its investment in the company's Australian operation. Credit:Reuters

Philip Morris Asia says the laws adversely affect its investment in the company's Australian operation, which was supposed to be protected under the 20-year-old trade treaty.

But the government has hit back, saying the challenge should be thrown out because Philip Morris Asia did not acquire its shareholding in the Australian operation until almost a year after the packaging policy was announced.