My father – in my mind because, aged 93, he has just died – used to take me to rugby internationals at Murrayfield in the 1960s. These were dominated by much kicking for positional advantage. Games were, depending on your point of vantage, fascinatingly tactical or grindingly boring. That experience prompts a pretty good metaphor for the report of the Bill of Rights Commission published just before Christmas.

The commission was set up to fail: it duly did. Indeed, it is difficult to remember a government committee that fractured so comprehensively. It even lost one member, Michael Pinto-Duschinsky, before it got started: he disagreed with its terms of reference. Of the eight left standing and his late-drafted replacement, only two (the former civil servant and the retired judge) resisted the desire to add a dissenting or supplementary opinion to the final report. Martin Howe QC associated himself with two, and Anthony Speight QC with three, while Jonathan Fisher QC, Lord Faulks, Lord Lester, Helena Kennedy QC and Professor Philippe Sands contented themselves with one apiece. All were playing for position in the debate that will follow. You can sense the relief of its chair, the smooth Sir Leigh Lewis, in the final draft. His main aim seems to have been to finish on time and within budget.

The commission has rightly come in for ridicule – not least from the member who resigned before it got started. The fault, however, is not really of the commissioners. They just have (and always have had) irreconcilable views, representing as they do totally different strands of thought. In addition, they were stitched up by the terms of reference. Deals between the two coalition parties meant they had to reconcile whatever they wanted domestically with continuing adherence to the European Convention on Human Rights. This logically leaves only two positions; stick to the convention or add to it. There is no place for anyone who wants less protection than the convention currently gives, something desired by half the remaining members and Pinto-Duschinsky.

Perhaps the most interesting finding of the report was the recognition, reported as coming ‘as a surprise’ to some commissioners, that the issue of the convention did not stand alone. The commission found that hostility to the European Convention on Human Rights and the Human Rights Act was a distinctively English problem. The Scots, Welsh and Northern Irish all rather liked both the domestic enforcement of human rights and their European articulation. The notion of a UK bill of rights clearly struck many of them, particularly the Scots, not only as ridiculous but inflammatory.

The true constitutional point is actually much wider. The move to weaken the bonds of the European Convention has to be seen in the context of a wider push to reassert ‘national’ sovereignty. It is deeply allied to opposition to the EU. This can sound very reasonable and even democratic when measured against UKIP’s current success as England’s answer to the Tea Party.

But, the paradox is that such an assertion of national sovereignty is likely to accelerate the fragmentation of the UK. The danger for those asserting such a literal ‘Little England’ policy is, as Sir Richard Branson and other signatories to The Times letter set out, that commerce and finance will just go elsewhere. So, too, may Scotland and possibly Northern Ireland and Wales.

The terms of reference of the commission were correct. It is madness for us to exit the European Convention. And the key debate among the commissioners is the one between Lord Lester, on the one hand, and Kennedy with Sands on the other. Like it or not, as a matter of practical politics, we are stuck with the European Convention. We can try to improve it. We can seek to reform the court that implements it. But it is playground politics to argue that the UK, or any rump part of it, would get any benefit from outside.

So, what is to be done? The answer is a grown-up debate that leads to acceptance of four coherent and inter-linked constitutional goals: retention of the union; the UK’s continuing membership of the EU; adherence to the convention; and some intermediate document that convinces the English public and media that human rights is largely just another phrase for age-old civil liberties that we have fought for over centuries.

That was effectively Lord Lester’s position. Kennedy and Sands thought the current atmosphere too poisonous to achieve this objective. They might well be right, but these should be the constitutional goals towards which we all work, regardless of political party. But, no wonder, in the short term, the commission’s report resembles those tactical, boring, rain-soaked rugby internationals to which my late and lamented father took me so many years ago.

Roger Smith is visiting professor at London South Bank University and former director of human rights group Justice