This week will see the by-election in Rochester and Strood, where Mark Reckless is standing for UKIP, having left the Conservative Party.

I thought it might be enlightening to look back over his parliamentary history and that of his predecessor Bob Marshall-Andrews (when the seat was called Medway) to see what we can learn from the topics they have raised in parliament.

But where to start?

Perhaps with a short comparison between Mark Reckless and the rest of his party. Since he joined parliament in 2010, Mark Reckless has been a little more active in debates than other Conservative backbenchers, but has asked far fewer written questions than the party average. The image above shows how frequently he spoke in debates over time, compared to the Conservative and all-party averages.

His favourite topics for written questions have been been aviation themed (in particular the Thames Estuary Airport), while various European issues have featured heavily in his contributions to debates – more on this later. The top topics for written questions for the Conservative Party as a whole were High Speed 2 and Wind Power – notwithstanding a lot of questions chasing up answers to members’ correspondence.

For a more detailed picture of Mark Reckless’s time in parliament as a Conservative – click here (if you’ve got a six & two threes account – or click here to sign up).

So what about the issues in play in this by-election?

Mr Reckless has helpfully provided a summary of the issues that he thinks UKIP will better enable him to tackle in parliament.

Topping the list are the NHS, Immigration, Public Finances and Europe.

How often did Mr Reckless raise these issues when he was a Conservative backbencher?

Europe came up quite a lot – in 13% of his written questions and a total of 134 times in the commons chamber – roughly once for every four times he spoke. Immigration was considerably further down the agenda – he asked no written questions about it, but raised it nine times on the floor of the house. The NHS featured in four questions questions and two of his speeches, while public finances featured in no questions, but four debates.

Contrast this with Bob Marshall-Andrews, who raised Europe a total of 17 times over a much longer period in parliament and only mentioned the NHS once – in a written question about thalidomide.

What next after Rochester?

We have seen speculation today about which Conservative MPs might follow Reckless and Carswell to UKIP – so I’ve had a quick look at what the data can tell us.

If we ignore David Cameron (who doesn’t have much choice about the topics he debates in parliament) and Bob Walters (who chairs the European Affairs Committee), there are 5 Conservative MPs who have given Europe a higher proportion of their debate time than Mark Reckless … I’ll post about them next week, but in the meantime see if you can guess who they are …