The low level skirmishes in the battle of Brexit have begun…..

News arrived on Tuesday that the Prime Minister was being a bit testy at the Liaison Committee. Ever anxious to monitor the PM’s state of mind, this sketch checked out the evidence only to discover that, yes indeed, Mr Cameron was displaying some petulance under questioning by the serried heads of Parliament’s select committees. The jacket was off though at least the sleeves were not rolled up. This suggested that he had arrived seeking to convey towards the Committee the appropriate admixture of insouciance and torso, but had not yet reached the stage of wanting to punch their lights out.

How long the peace might have been preserved had the questioning remained with Andrew Tyrie, the Commttee’s Chairman, is an interesting question. Mr Tyrie picked an early fight with the PM over his attendance rate before the Committee, before moving on to question him about progress against ISIS. To develop his questioning style, Mr Tyrie has dipped deep into the treasury of condescension and possesses a languid manner of interrogation suggesting that in the movie version he would have had to be played by the late Alan Rickman. Mr Cameron, doubtlessly fancying a portrayal by a young, but now alas equally late David Bowie, answered as politely as he could, which was not very.

You could see him straining equally when the questioning was taken up by Harriet Harman (Emma Thompson, natch) who was anxious to burnish her credentials as a Labour moderate by asking him about UK drone strikes. Corbynite policy is to oppose the killing of the country’s enemies – a position borne of convictions that are part pacifist and part swayed by the belief that the enemies are right and we are wrong – while Ms Harman conveyed the impression that she was not entirely opposed to this, especially if the enemies were men. Nevertheless, her conscience, not to mention her lawyerly training, told her that the killing needed to be wrapped in sufficient layers of ex ante legal process and post hoc investigation so as to satisfy the demands of armchair pacificsts such as herself. Mr Cameron seemed to think that the current system would do. Who knows? The fact that UK drones do not routinely rain down on council tax evaders, benefit cheats or toffee-nosed committee chairs may speak to admirable self-restraint, adequate regulation or the lack of defence budget, or a combination of all three.

Equally testing Mr Cameron’s patience this week was Chris Grayling, his Cabinet colleague, who declared in a column in the Daily Telegraph that Britain’s membership of the European Union is “disastrous”. Readers of the Daily Telegraph do not need to be told this: the purpose of Mr Grayling’s article was to signal that the low-level tactical deployments of the referendum campaign have begun. The “remain” side of the argument reacted proportionately with an article in the Observer by Nicky Morgan, aka NiMo, the Education Secretary and ‘minister for women’. The EU is good for women, Ms Morgan argued in some unspecified way, raising the intriguing possibility that if women vote stay and men to leave in Mr Cameron’s referendum, the UK may have to fracture along gender lines. At some point, politicians people have actually heard of may have to get involved in this debate, though the precedents are not helpful: everyone has undoubtedly heard of Nigel Farage but the problem with his involvement is that it is better at bolstering support for the other side than for his own.

While pausing on the subject of non-entities, there was also a brief cameo from Nick Clegg on Sunday’s Andrew Marr show. He seemed keen to support the Prime Minister’s new line on Europe that Britain should remain in the Union for the sake of our security. “There is safety in numbers”, Mr Clegg argued, which, if true, would suggest that Liberal Democrat members of Parliament should be among the most terrified people in the country. Over in the Lords, where there are dozens of unelected Lib Dems, one caught one of these, Lord Rennard, arguing vigorously in favour of imposing a tax on sugar-laden drinks. Not a man who looks as if he has supped overly long at carrot juice, Lord Rennard deployed the ingenious argument that either the tax would work – in which case people would become thin and Coca Cola go out of business – or it would not, in which case the Treasury would harvest vast sums to give to the NHS to treat fat people. It was good to see Lord Rennard remaining loyal to the essential barminess of Liberal Democrat policy positions. Lechery not treachery has always been his problem, though, of course, he denies both accusations.

The Mayor of London, Boris Johnson, is in favour of an impost on sugary drinks, having introduced such a policy in City Hall, while the Tory minister grappling with Rennard, a cadaverous cove called Prior, seemed disposed against. One did not really get a sense of Labour policy on the matter, though one presumes that it would be to endorse such beverages so long as they don’t have any sugar in them. This would put the matter at one with Mr Corbyn’s new defence policy which is to support our fleet of nuclear submarines so long as they are not actually armed with nuclear weapons.  The subs, rather like Islington in the good old days, would proudly bear signs declaring themselves to be nuclear-free zones.

This represents a subtle, but important, evolution of Mr Corbyn’s defence policy. Previously he was clear that he wouldn’t use the nuclear weapons that we have. Now he is not going to use the weapons that we don’t have, though for some reason keeping hold of the vessels where we wouldn’t have them.  Presumably the general idea is that our enemies would get so lost in the thicket of double negatives that they would retreat in confusion anyway.  Either that or they would fall over laughing. This is a small idea lost within a bigger idea: the bigger idea is not to upset the trade unions upon whose financial support the Labour Party depends.