Donald Macintyre's Sketch: David Cameron’s drive for a Mark Reckless-free Rochester

Once Prime Ministers didn’t much go to by-elections. Five times at Newark alone, David Cameron is already sure to make the Guinness Book of Records as the most persistent by-election campaigning PM in history. But today he set a more startling precedent: campaigning before there was even a candidate!

But these are desperate times. Now that, as he explained, Mark Reckless had taken the “baffling” decision to leave his party and force a by-election in Rochester and Strood there were several messages to get across.

So flanked by local businesswoman Kelly Tolhurst and not quite so local barrister Anna Firth, contesting the forthcoming “postal primary” and neither seeming to be exactly entranced with the other – he happily answered two convenient questions on Europe and especially immigration in the Wainscott Memorial Hall.

Indicating there was more to come on this – and to take a wild guess it could be before polling day on 20 November – he said the Tories wanted “further action… to make sure we have more effective control of migration”. He didn’t go as far as Ms Firth who said on Wednesday that she wanted a points system like that for outside the EU, which would bar, say, “a fruit picker in Romania”. But then he wasn’t giving details. And this was all part of “one last go at negotiating a better deal with Europe.… We don’t want a European army and a European flag or European country. We live in a country called Britain.”

The candidates themselves sensibly kept to local issues. One surprise was a question on bringing “the church closer to the state”. Ms Firth said she “absolutely” agreed as a lifelong churchgoer; Ms Tolhurst was slower in getting to the importance of working with churches and other voluntary groups. In the unlikely event that disestablishmentarianism becomes the primary’s key issue, Ms Firth could edge it.

But both candidates rose enthusiastically to a sombre invitation from Tory stalwart Peter Hart, 67, to “tell us that you will never, ever lie to us like the Ukip candidate has. He lied and lied and told blatant untruths and… we will never ever forgive him.” For a second we wondered if one of them might say: “Well hang on, I’m trying to be a politician, I can’t really promise that.”

But no. “I’m really proud to be a Conservative,” declared Ms Firth. “I’m never going to be anything else.” Ms Tolhurst: “Absolutely not I will not lie to you. Mark Reckless, to me, in his decision was completely irrational and I find it quite crazy what he’s done.”

This allowed Cameron to announce: “I think what you’ve seen is that if you choose either of these candidates you’re not going to get someone who’s interested in playing Westminster party games, or the nonsense we’ve had with Mr Reckless.” (There are times he sounds perilously close to Private Eye’s headmaster parody.)

Away from the hall, voters were warily divided. Probable Reckless voter Frieda Aitchison, “I think he’s done quite a lot for the area”, was cross that the PM’s meeting delayed her setting up the pensioners’ bingo she organises in the hall and that local Tory Tom Mason had been dropped from the Medway authority Cabinet after 30 years’ service on the council. Admittedly he’s 80. But that cuts little ice with her since she’s a spritely 86. Her friend Edna Parfitt said she would not vote Ukip because “it’ll go Labour and I don’t think they’ll be able to do much”.

The taxi driving community was also divided. Don’t know Tom Plunkett, 37, worried about the NHS and youth unemployment, said “I don’t like Reckless much but I sort of respect him.” But a colleague said: “Why don’t I like him? Because he’s not a nice man”. Maybe this by-election will be all about Europe and immigration. But for now it seems to be about Mark Reckless.