Judith Collins' woes have some striking similarities with those that drove her former colleague Pansy Wong out of Cabinet and Parliament.

While on trips to China, both visited businesses in which their husbands had an interest. Both visits were proudly highlighted by the companies on their websites, giving the Opposition ammunition.

But while it was questions around Mrs Wong's and her husband Sammy's use of taxpayer-funded travel perks that eventually forced her out, the questions around Ms Collins relate to whether she used her influence as a minister to advance her good friend Deyi Shi's business interests and, to a lesser extent, those of her husband, a director of Mr Shi's milk export company Oravida.

Mrs Wong quit Parliament in 2010, knowing Labour's chief dirt digger, Pete Hodgson, had fresh information she might have misled an inquiry into her and her husband's use of travel perks.


She resigned as Minister of Ethnic Affairs and Minister of Women's Affairs a few days earlier after it emerged she and her husband had breached parliamentary rules by conducting business activities during a series of trips to China partly taxpayer funded through her use of the MPs' travel allowance.

An investigation found that one trip, a flight from Beijing to Lianyungang, China, in December 2008, could have been in breach of the rules because when in Lianyungang, the couple engaged in private business activities.

Ms Collins' status as a minister was highlighted on Oravida's website after she visited the company's Shanghai office last year. What's more, a translation of the accompanying Chinese text has her praising the company's milk. The Opposition says that amounts to an endorsement, which would be against Cabinet rules. The Cabinet Office has advised Prime Minister John Key that's not the case.

Ms Collins, whose husband was not on the trip, is in deeper water over her dinner a few days earlier with Mr Shi and a senior Chinese border control official.

For now, her biggest crime is not telling Mr Key and the media about it earlier. Mr Key has indicated that she may lose her portfolios if she makes another misstep.

The Opposition are accusing her of using her ministerial influence with the border control official at the Beijing dinner to remove obstacles to Oravida's milk exports to China in the wake of the Fonterra botulism scare. While a sackable offence, that will be difficult to prove, but if there is any other halfway credible evidence she has intervened to otherwise assist Oravida, she will face the same fate as Mrs Wong.