I'll begin with long-serving BBC irregular Brian Hanrahan. His only previous appearance on this blog was for an interview with Ed Balls (Labour) (26/6), which scored a lowly 0.2.
His return in August gave listeners 4 interviews to savour - and, most unusually, 3 out of 4 of them were with Conservatives.
Here are August's interruption coefficients for Brian Hanrahan:
Timothy Kirkhope, Conservative (14/8) - 1.4
Andy Burham, Labour (14/8) - 0.9
Gerald Howarth, Conservative (3/8) - 0.3
James Arbuthnot, Conservative (7/8) - 0
Average number of interruptions per political party:
Labour - 0.9
Conservatives - 0.6
The evidence for bias here is, I think it's safe to say, contradictory. Note though that the top two scores were on the same programme & on the same subject - Dan Hannan's comments on the NHS - and, so, are directly comparable.