When Liberal MP John Alexander was first outed as a potential UK dual citizen he claimed he was in the clear because his father had renounced.

But he couldn't prove it.

Labor MP David Feeney is going to the High Court because he cannot prove he renounced his UK citizenship. Credit:Alex Ellinghausen

He had no documents to back up his story; and neither, it seemed, did the UK Home Office. Meaning no such documents existed.

He looked like a complete dill, of course, but instead of wasting the High Court's time in a cynical bid to cling to his job he did the right thing: within a few days he had resigned from his seat, sparking an immediate byelection.