Conservative plans to take power away from Strasbourg will not stop Supreme Court from enforcing human rights.

What issues will divide the parties at the next general election? Housing? Jobs? The economy? Might the law get a look-in for once?

I am not talking about legal aid, where the differences between the politicians seem to be ones of style rather than substance. Instead, the issue on which the Conservatives threw down the gauntlet to the other main parties at their conference last week was human rights.

‘We are the only major party committed to radical reform of human rights laws,’ said Chris Grayling, the justice secretary. ‘Labour are opposed. The Liberal Democrats are opposed.’ He promised his supporters that the Conservatives would ‘go into the next election with a clear plan for change’.

But what will it say? That is rather harder to find out.

At the domestic level, both Grayling and Theresa May, the home secretary, promised to ‘scrap’ the Human Rights Act 1998. But their careful use of casual language does not preclude the possibility that the act would be replaced by something else. Grayling hinted as much when he promised to ‘make sure that with legal rights go legal responsibilities’. But that was as far as it went.

The two secretaries of state were both much more circumspect about the UK’s relationship with the human rights court. May explained that Grayling was currently ‘leading a review’ of this relationship. She then said: ‘If leaving the European convention is what it takes to fix our human rights laws, then that is what we should do.’

And if it was not? The home secretary did not say. Nor did she specify in what way human rights needed to be ‘fixed’. Grayling appeared to be a little more forthcoming.

‘Our Supreme Court should be in Britain and not in Strasbourg,’ the justice secretary insisted. ‘A future Conservative government will do whatever it takes to ensure that it is.’ The justice secretary had used almost identical language in an interview with the Spectator a few days earlier, prompting his interviewer to infer that he wanted the UK to leave the jurisdiction of the European Court of Human Rights; otherwise, the journalist pointed out, the Strasbourg court would always be supreme.

But giving up the court’s jurisdiction would mean withdrawing from – or ‘denouncing’ – the human rights convention. Was that what Grayling intended?

Not necessarily, he told me just after his speech in Manchester. And how could it be otherwise? ‘I have lots of clever lawyers who can help,’ Grayling said mysteriously. We would simply have to wait and see. There would be a consultation paper in the new year, to be followed by a draft bill next autumn.

Those clever lawyers – who are not part of the Government Legal Service – will have told the justice secretary that, in a sense, the Supreme Court is already supreme. Strasbourg judges have never been able to overrule decisions taken by domestic courts. All they can do is to declare that there has been a breach of somebody’s human rights, leaving it to the government to put things right. And the Human Rights Act says only that UK courts must take Strasbourg decisions ‘into account’, not that it is bound by them.

Perhaps Grayling wants to change that ‘must’ to ‘may’, or scrap the link with Strasbourg rulings completely. On the face of it, that would give the domestic courts even greater discretion. But our courts are well aware that a disappointed litigant can always seek to take a case to the human rights court. That is why they try to keep our law in line with Strasbourg decisions. They will surely continue to do so unless the UK pulls out of the European convention.

And how does the Supreme Court itself feel about Grayling’s plans? ‘I do not think it is politically controversial that some form of human rights or citizen’s rights against the state are encoded or enshrined in a statute or some similar document so that they can be enforced in the courts,’ Lord Neuberger, the court’s president, told reporters last week. ‘It seems to me that the most important principle is that we have enshrined in our law, as we do at the moment, human rights, whether in the form of a statute, under the Human Rights Act 1998 or in the form of some sort of constitution or conceivably some other form.’

Does that mean the courts would uphold human rights even if the act was abolished? Lord Neuberger seemed to think they would. ‘What could happen… is that if we did not have the Human Rights Act, the common law might develop in certain directions to accommodate a degree of change – because the common law does change with the times.’

Grayling should be careful of what he wishes for. Making the Supreme Court supreme will not stop it enforcing human rights.