Away from the blood and thunder courtroom law, a lot of the work undertaken by a lawyer is negotiation. Negotiation is something I do on an almost daily basis in my professional life and over the course of my career I have negotiated perhaps several hundred settlements. This variety of experience has taught me a lot about what approaches do and (just as crucially) do not work.

The rightwing press were beside themselves with glee last month when Theresa May, chest puffed out and jaw clenched, promised to be “bloody difficult” with her European counterparts when it comes to the Brexit negotiations. Here was someone prepared to stand up to Johnny Foreigner; someone who would swagger into the negotiating room knowing no fear and if Jean-Claude Juncker tries any of his perfidious mischief on her, she will draw a union jack knuckle duster from her clutch purse and beat the buffoning, blaggard bureaucrat back to Brussels.

Yes, May would be rough, tough and uncompromising in her pursuit of the best deal for Britain.

But therein lies the problem: while the hardnosed, no-nonsense negotiator may look good in a tabloid headline or sound good in a Shropshire beer garden, an ultra-aggressive approach is the least likely to translate into a favourable result at a negotiation. The hard-man rhetoric has no basis in the realities of real life negotiation. Nothing, but nothing, is more likely to make me say “I’ll see you in court” to another lawyer than his taking an approach I find to be too aggressive.

The purpose of negotiation is to resolve a dispute in a manner acceptable to both parties. This makes at least some degree of compromise inevitable. Yes, you could go to court and, if you win, you will (at least in theory) get the full amount. But that takes time, money, effort, a great deal of emotional stress and carries with it the risk you will either lose or end up will less than you could have settled for. The degree to which you are willing to compromise is therefore price you place on avoiding those pratfalls.

So this is your starting point: something will have to go. There are things you need, things you strongly desire and things you would like. The first are your non-negotiables, the second your red lines and the third your bartering chips.

In order to successfully negotiate, you first need not only to rank your preferences, but also to understand those of your opponent. If you do not do this, you will not know which issues they are willing to concede cheaply and which are going to take more effort. Understanding and listening to your opponent is the first step to achieving as close to an optimal outcome as possible.

Of the two party leaders in the running for Prime Ministerialship, Jeremy Corbyn is by far the better placed to negotiate a good deal on Brexit.

The Conservative party is beholden to the far right of British politics: they have seen a swing of 9% of votes from UKIP between the 2015 General Election and this current campaign. This 9% is likely to be greater than the Conservative margin of victory in this election. In other words, whether or not Theresa May will continue in her role as Prime Minister after 8 June will depend on her ongoing ability to prevent those voters dripping back to UKIP. She is therefore committed to publically refusing to countenance any compromise on the Brexit negotiations, something which will likely be deeply damaging to the prospect of the talks proceeding in anything approaching a conciliatory tone.

Corbyn, on the other hand, has a far freer hand. He has license to pursue a more open and conciliatory approach. The reason the media have been able to run with the May-as-strongman line is that it is consistent with her public persona: cold and uncompromising. Corbyn is more genial and able to exude greater bonhomie than May. These are the tools needed in negotiation: it is a lot more difficult to say no to someone if you genuinely like them.

Another quality that makes it difficult for people to say no is the ability to convey through reason why a red line issue is a red line issue for you. If your opponent understands why you are unwilling to concede a point, they are more likely to accept that it is something not worth bickering over. In this respect, probably better placed than either May or Corbyn is Nicola Sturgeon, with her unrelenting sharpness of mind and her gift for debate. May’s dogmatism and unwavering “Brexit means Brexit” attitude again leaves her bottom of the pile.

In law, any negotiation is always underpinned by the ultimate threat of court action: if the parties cannot work things out sensibly between themselves, a judge will decide in a winner-takes-all decision. In international relations, the stakes are higher and the outcomes even less predictable. An aggressive, unfriendly and unyielding approach that alienates Europe and leaves the parties unable to reach an agreement could leave the UK economically and diplomatically isolated. Economically, that would be catastrophic: a rocky island perched on the North-West shoulder of the world’s largest trading block, cut off from access to its markets. Diplomatically, it could be even worse: cooperation between the European states is absolutely essential given the current instability in the world. A deal is therefore essential and compromise, no matter how little the swashbuckling, browbeating headlines in the rightwing press want to hear it, will be a necessary part of making a deal.

To this end, a victory for Jeremy Corbyn, perhaps backed up by Nicola Sturgeon’s SNP, is the best chance the UK have of getting the right result from the Brexit negotiations.

Blog by Michael Briggs