If correct, the evidence presented at the Independent Commission Against Corruption has exposed the troubling nexus between political party funding and the potential influence of donors on policy matters.

The Liberal Party was not short of money in the lead-up to the March 2011 poll; it was the unbackable favourite to take government.

But election campaigns are hideously expensive. O'Farrell, then opposition leader, felt the need to tap head office for some cash to fund a researcher. Matt Crocker was employed in his office as a policy manager.

This in itself was not unusual. But former Liberal fund-raiser Paul Nicolaou has given evidence that Crocker's position was at least partly funded by a donation from Brickworks.

ICAC has also heard that a Brickworks donation of $125,000 to the Free Enterprise Foundation was in turn donated by the foundation to the NSW Liberals for use in their campaign. At the time developers were banned from making political donations in NSW elections.

That's where things begin to get seriously problematic.

Two weeks before the election O'Farrell made a policy announcement at Brickworks: a commitment to repeal an unpopular property tax. It stood to benefit not only the company but the entire property development industry, which Brickworks supplied.

This raises a number of questions. Did Crocker have input into that policy? If so, was his input coloured by the funding arrangement? Or did the illegal $125,000 donation influence the policy?

Nicolaou's evidence is that he didn't think O'Farrell was aware Brickworks was funding Crocker. O'Farrell will give his version when he enters the witness box on Tuesday.

But can it just have been a coincidence that O'Farrell chose to attend Brickworks to announce the policy?

Whatever the case, the perception is damning. It's yet another reason Premier Mike Baird needs to move to break the toxic relationship between donors and political parties in time for the March poll.