I've had four conversations of varying lengths with sitting and former MPs down the years which all took place on trains, two were London underground ones. One was a Tory, John Redwood, two from Labour, Kim Howells and Dianne Abbott, and one from Plaid, Dafydd Wigley.

I found the first three to be stand-offish. Redwood was every bit as Mr Bean-ish as he looks.

Wigley though was very personable. Although I suspect he was more so as he spent much of the Paddington to Swansea choo-choo journey stood at the buffet car swigging grog.

He made various ambiguous remarks hinting that the Commons was full of play actors who had few if any real political convictions. He said something along the lines of: the primary objective of every MP is to remain one for as long as possible.