I have always been fascinated by the law of unintended consequences. It was as a result of this law that the Millennium Dome turned into an expensive white elephant. And I suspect we shall see it operating again in three years, when another of Lord Falconer's make-overs achieves maturity.

Under the Lord Chancellor's plans, the law lords are to be given a new name and a new building. Strictly speaking, both the name "supreme court" and the building in which it will sit are second-hand. For practical purposes, though, Britain will have a new final court of appeal in 2009.

Lord Falconer's intention is that the judges of the supreme court will have no greater powers than the law lords have now. But this is where the law of unintended consequences kicks in.

Once you call a group of judges the "supreme court", there is every chance they will start to behave like the supreme court we all know best, the one in the United States.

What distinguishes the US supreme court from its present British counterpart is the power to strike down statutes that conflict with the constitution.

Surely our judges would never seek to overturn an Act of Parliament? That is what they usually tell you. But look what the law lords said last October, when nine of them dismissed the final attempt by the Countryside Alliance to establish that the Hunting Act 2004 was not a valid Act of Parliament.

Lord Steyn believed there might be circumstances in which the courts might not enforce oppressive legislation introduced, like the 2004 Act, without the support of the House of Lords.

The supremacy of Parliament was simply a principle established by the judges, he explained, and if the courts could make it then the courts could modify it.

"In exceptional circumstances involving an attempt to abolish judicial review or the ordinary role of the courts," Lord Steyn said, "the [law lords] or a new supreme court may have to consider whether this is a constitutional fundamental which even a sovereign Parliament acting at the behest of a complaisant House of Commons cannot abolish."

Lord Hope agreed that "sovereignty is no longer, if it ever was, absolute". And Lady Hale said the courts would "treat with particular suspicion (and might even reject) any attempt to subvert the rule of law by removing governmental action affecting the rights of the individual from all judicial scrutiny".

These comments led Prof Vernon Bogdanor - who will be forever known as David Cameron's Oxford tutor - to say in his Magna Carta lecture this month that the conflict between the sovereignty of Parliament and the rule of law, if not resolved, could generate a constitutional crisis.

In my view, it would need a government even less committed to the rule of law than the present one for our judges to start overturning legislation. But just assume for a moment they wanted to. How could they manage it?

The answer is to be found in a new book by Aharon Barak, shortly to retire as president of the supreme court of Israel.

The Judge in a Democracy (Princeton University Press) explains that there was nothing in either the US or the Israeli constitutions allowing judges to strike down acts of the legislature.

Even so, he says, the courts in both countries have held that judicial review of legislation is implied by interpretation of the constitution.

"In the United States, this ruling was made in 1803. In Israel, it was made in 1995. In both countries, there are still those who argue against the legitimacy of these rulings," the court president writes.

"In the US this argument is on the wane. But in Israel it is still alive and vibrant, particularly because some of the founders of the Israeli constitution are still alive, and they do not hesitate to state their opinions on the rulings of the supreme court."

Like Britain, Israel has never had a comprehensive written constitution along US lines. But what the Israeli parliament, has done is to pass a number of so-called basic laws.

Israel's supreme court decided in 1995 that two such laws had higher constitutional status than ordinary laws. They entrench human rights, which means they are harder to amend or repeal than ordinary laws - rather as Mr Cameron would like to do in Britain with his planned Bill of Rights.

"Judicial review of the constitutionality of laws impinging on human rights has become the norm in most countries," President Barak noted in the Mizrahi Bank case of 1995. "This revolution has not passed us by."

He said there was no express provision in the two basic laws allowing them to trump other statutes.

It was not something, he thought, that would be permitted under British notions of Parliamentary sovereignty - though, as he pointed out, Prof Ronald Dworkin said in 1990 that "legal history and practice can change with great speed".

But, said President Barak, the Israeli parliament had the power to enact human rights laws with "constitutional-super-legislative status". If a subsequent "ordinary" law breached human rights, explicitly or implicitly, the court could declare it invalid.

This "constitutional revolution" as he called it, was not widely noticed at the time, perhaps because it coincided with the assassination of the prime minister, Yitzhak Rabin.

As President Barak acknowledged, there is now a lively debate in the Israeli press over the proper boundary between independent judges and elected politicians.

Both sides, inevitably, claim they are upholding the will of the people, as expressed through what is their understanding of the nation's constitution.

So, will Mr Cameron's planned Bill of Rights put the judges back in their box, allowing governments the freedom to govern? Or will it give the judiciary a means of striking down Acts of Parliament, cutting over-mighty ministers down to size?

The only certainty is that we will not know until it happens. That, after all, is what the law of unintended consequences is all about.