If some prince in the past had actually been the bastard son of the queen's paramour, then the current line is invalid.
The correct line of succession leads to a middleclass family man living in ... you guessed it ... Australia.
A middle class family man who was the 14th Earl of Loudoun (he died in 2012, and his son is now the 15th Earl).
The argument is that if Edward IV was illegitimate (which is quite possible - there are questions as to whether his 'father' Richard, Duke of York, was anywhere near his mother at the time of conception). If that was true, George, 1st Duke of Clarence should have become King instead of Edward IV, and the Earls of Loudoun are the senior surviving heirs of the George of Clarence.