Even if, by some narrow interpretation of the guidelines for ministerial conduct, Stuart Robert is formally in the clear on his conduct with Liberal donor Paul Marks and the latter’s dealing with Chinese companies, Robert should resign.

Robert has shown a failure to understand that, as a minister, he is always seen as that — particularly when overseas — and that any “private” action he takes in relation to an Australian company unmistakably comes with the assumed imprimatur of his government.

That is why ministers, far more so than backbenchers or opposition MPs, should not engage in business activities, even if they are unrelated to their portfolios. Taxpayers remunerate them well; taking leave to be a shill for a corporate mate fails a basic test of judgement.

As Crikey has argued over and over, we simply aren’t given enough information under existing donation laws to enable effective scrutiny of the union of interests between business and politicians. Businesses, both domestic and foreign, have a strong incentive to get into politicians’ good books. And politicians have a strong incentive to raise money to fund the cost of political campaigns.

Robert’s conduct is yet another example, not only of why we need stronger political donations laws, but also why ministers and shadow ministers should be compelled to make their diaries public. By significantly enhancing transparency about who is meeting with and donating to senior politicians, the rest of us will be able to see more of what really goes on in the currently murky world where politics meets business.