Wilkie says he'll withdraw support, even if it's Abbott who kills gambling reform.

Imagine, if you will, this scenario - a prime minister desperate for support to form minority government enters an agreement with an independent to tackle problem gambling. Despite good faith and considerable effort over several months, the reform lacks sufficient parliamentary support to become law. The opposition blocks it, the crossbench splits and a mandatory precommitment scheme dies a natural death. Good riddance, says most of the Parliament.

What would that independent do then? Would he shrug his shoulders and say, ''Fair cop, Julia can't control everything''? Or would he sense a political stitch-up? Would he do what he threatened he'd do and bring down the government?

If the independent is Andrew Wilkie, which it is, he will bring down the government, plain and simple. He told me that yesterday, plain and simple, even though his disposition is to praise Julia Gillard. What if the legislation is blocked? ''I would pull my support. My support for the government hinges on this.'' Even if it's not Gillard's fault? After all, she can't control Abbott. ''This will be a test of her leadership,'' he says.

Given this is not a hypothetical but a real and present situation, that is quite the sword of Damocles for Gillard. Expect to hear a lot more about gambling over the next few months. So far the issue has lurked below the radar, allowing some powerful interests - pubs and clubs - to run the most ferocious lobbying campaign seen in Canberra since the mining tax.