Bart Bassett's announcement on Wednesday brings to nine the number of MPs who have stood aside from the parliamentary party pending the outcome of Operation Spicer, the Independent Commission Against Corruption's investigation into illegal political donations.

Two of those, Andrew Cornwell and Tim Owen, have also resigned from parliament.

Bassett's move brings ever closer the real prospect of the casualty list hitting double figures, given the inquiry has potentially a fortnight to run.

Obviously, the Liberals are doing what they can to distance themselves from possible adverse findings or damning evidence down the track.

But the way this inquiry is unfolding means no one in the party, from Premier Mike Baird and state director Tony Nutt down, can be confident of where it will end.

What is likely to send the biggest shivers down the spines of party bosses, though, is not the mathematics. It is the geography.

Until now, the evidence paraded before Operation Spicer has suggested the alleged and actual rot was confined to the central coast and the Hunter.

That was at least some small comfort to party bosses, given they were areas in which the Liberals unexpectedly won seats at the 2011 poll in Barry O'Farrell's landslide victory. They were traditional Labor strongholds that were expected to naturally swing back to Labor in 2015.

So while the reputational damage to the Liberal Party is real, in many respects the likely electoral outcome was already being anticipated.

The alarming thing for the Liberals is that Bassett holds the seat of Londonderry in Sydney's north-west.

This doesn't mean the latest evidence signals the region is necessarily tainted by allegations of corruption. At this point there's no evidence of that.

It's actually much worse, because it is confirmation illegal donations could have been offered and accepted wherever a property developer - banned donors since 2009 - was seeking a political favour from those coming into government.

Alarmingly for the NSW Liberal party, that's potentially any seat it holds across NSW.