Twenty years ago this autumn, a revolutionary new law came into effect. Although the Human Rights Act had been passed by parliament in November 1998, the government waited until 2 October 2000 before bringing it into force.

That was not because Tony Blair had second thoughts about one of his government’s earliest reforms; judging by the single sentence it rates in his 700-page memoir, Blair gave it very little thought at all. It was because the senior judiciary wanted every judge in the UK to be trained in the new law before they were let loose on it.

The legislation was designed to allow people in the UK to enforce the rights they had enjoyed since 1966 under the European Convention on Human Rights — but without needing to take the government to the human rights court in Strasbourg. For the first time, they could use the convention in their own courts.

The Human Rights Act positively encourages judges to rewrite statutes

Unlike their counterparts in the US, senior judges in the UK cannot overturn legislation as unconstitutional. But if they consider that a statute does not comply with the human rights convention, the act allows them to make what’s called a declaration of incompatibility. That gives parliament an opportunity to change the law — and one it often takes.

Enacting new laws is very much a last resort. Instead, judges are told they should try to interpret existing legislation so that it complies with the convention and rulings from the Strasbourg court. This power — a duty, in fact — is known as “reading down”. It applies only where judges think it possible to read domestic legislation compatibly with convention rights: they are told not to adopt an interpretation that “goes against the grain” of a statute. But the Human Rights Act positively encourages judges to rewrite statutes, enlarging on their long-accepted powers to develop the common law.

Have judges run riot with the rights act? There are certainly examples of senior judges reading down legislation in line with changing social values. But the judiciary have baulked at changes that might be regarded as controversial — rewriting statutes to allow divorce on demand, for example, or to legalise assisted suicide. As the judges acknowledge, such matters are best left to parliament.

One area in which the Human Rights Act has had a significant impact is the law of privacy. Thirty years ago, no such law existed: there was nothing to stop a reporter and photographer from a Sunday tabloid walking into a private hospital ward and taking advantage of a popular television actor who was recovering from emergency brain surgery.

It was not until 2004 that the model Naomi Campbell won her claim against the Daily Mirror for publishing pictures of her leaving a Narcotics Anonymous meeting. A decade later, the BBC left itself vulnerable to a successful claim from Sir Cliff Richard when it broadcast helicopter footage of the entertainer’s home being searched by police: no charges were ever brought.

And now the Duchess of Sussex is suing Associated Newspapers for publishing extracts from a letter she had sent her father, Thomas Markle. In response to her privacy claim, the publishers say they had a public interest in scrutinising working members of the royal family.The European convention protects an individual’s private and family life just as it protects a newspaper’s freedom of expression. It was by balancing those competing rights that the judges developed a privacy law in England and Wales. But I am confident that the courts would have achieved a similar outcome even if the Human Rights Act had never been passed. As long ago as 1996, the distinguished judge Lord Bingham was predicting that the judges would protect personal privacy by developing the common law. If the act were ever to be repealed, the judges would fill in the gaps.

However, there seems no prospect of repeal – and Brexit will have no effect on the human rights convention, which has nothing to do with the EU. On the contrary, the government is reinforcing the Human Rights Act, though in a way the government’s supporters might not have expected.

In March, just before the lockdown, the Ministry of Defence published its Overseas Operations (Service Personnel and Veterans) bill. The main aim is to introduce a presumption against prosecuting serving or former service personnel for offences they are alleged to have committed during operations overseas more than five years earlier. But the bill would also add two new sections to the 1998 act.

Twenty years on, the Human Rights Act has stood the test of time

Section 7A would introduce new time limits for judicial review claims against the Ministry of Defence relating to overseas military operations. And section 14A would require a cabinet minister to consider derogating — temporarily withdrawing — from the human rights convention for significant overseas military operations.

There would be no point in introducing these amendments if the Human Rights Act was at risk of repeal — still less if the UK was considering withdrawing from the human rights convention and the Council of Europe that supervises its operation. Twenty years on, the Human Rights Act has stood the test of time.