Britain’s most senior law lord is looking remarkably relaxed, given the weighty legal and constitutional matters on his mind.

Lord Bingham of Cornhill, senior law lord, attired in woolly jumper, was on a reading day in his room in the House of Lords that is the law lords’ corridor. Just the day before, in a lecture at King’s College London, he highlighted the “serious problem” that Britain’s constitutional settlement had become “unbalanced” and the power to “restrain legislation favoured by a clear majority of the Commons much weakened, even if, exceptionally, such legislation were to infringe the rule of law”.

He hopes Gordon Brown’s review of the governance of Britain will put this issue high on the agenda. But the much-vaunted bill of rights is not necessarily the answer, he says. “I’m puzzled because we are bound by the European Convention on Human Rights . . . it seems inconceivable that the UK would remove its membership of the Council of Europe, so the international obligations we then assumed remain binding on us.”

Any bill would either duplicate the convention or must be different and additional, he argues. The Government plans to build on existing rights and spell out duties. “It is not absolutely plain what duties it would impose . . . you could impose a duty to obey the law, but that exists; you could spell out that you must pay your taxes, but we all know that. I don’t suppose it will say: you have a duty not to barge in front of the bus queue.” As for new rights, such as environmental rights, they are catered for in existing law, much deriving from Europe. “So I don’t really see the point of it.”

Lord Bingham, 74, has led the highest court of the land for seven years. In that time there have been increased tensions between the judiciary and executive — not least over rulings involving the Human Rights Act.This, critics say, has enlarged judges’ powers, drawing them into uncharted and controversial decisions. But Bingham rejects the notion that a bill of rights would further increase judges’ power. “I don’t see these things in terms of power. The Human Rights Act required us to make judgments we’d not done before and no doubt a bill of rights, if enacted, would require us to make still more judgments.”

What will increase their profile, though, is the new supreme court. Scaffolding is up outside the Middlesex Guildhall in Parliament Square and the court should open in October 2009. Bingham, a strong advocate of removing the law lords from Parliament and putting clear water between the judiciary and legislature, says he will be “very sorry” not to be its first president. “I was in favour of the project, but not an admirer of the building,” he admits. But he agrees that “if you want to make the point that this is an important pillar of the Constitution, there is no better place, physically or geographically. And a huge amount of work is being done to try to adapt the building to our particular needs.” He is confident that it will achieve “a very good result”.

The court would increase public understanding about who the law lords are and what they do. “People have very little idea.” Coverage of the control orders ruling was illustrated in one newspaper by a group of judges, not law lords, at the state opening, “wearing wigs and robes we don’t wear”. But he is against allowing TV cameras to broadcast law lords’ sittings — something Jack Straw thinks worth looking at, if judges approve. “I would not mind a photograph of members of the court assembled on the bench before the hearing starts. But I certainly don’t want cameras in the hearing — it would be completely unsatisfactory.”

He makes the point that law lords’ hearings, in which the judges try in advance to assimilate large amounts of paper “to deter counsel from telling the whole story from A to Z” and to go straight to the points in contention, would be “completely incomprehensible to a TV viewer”. Only excerpts would be broadcast and not reflect the nature of proceedings. “If one asks oneself — has televising of the House of Commons increased public respect for its activities, the answer would be ‘no, I don’t think it has’.”

As for the kind of work that the supreme court will do, he does not envisage much change. “There are those who think that judges will have a great rush of blood to the head and a lot of powers that they didn’t exercise before, but I simply don’t accept that for a moment. It will be business as usual.”

Bingham declines to comment on relations between the judiciary and executive, saying that he simply “does not know”. One of the joys of his job, he admits, is that he has been free of such matters and of the administration that comes with the post of Lord Chief Justice, which he held before his present job. Before that he was Master of the Rolls: in all three posts he has been hugely admired and respected in legal circles; it is no coincidence that he is the first judge to have been made a Knight of the Garter — but with typical modesty does not like reference to it.

In the highest court, his tenure has seen some of the most controversial hearings in recent years: the Belmarsh case on the illegality of holding terrorist suspects without charge; and the ruling on torture evidence being just two. He declines to single out key rulings — their significance, he says, can be seen only in hindsight. Nor will he pick out procedural reforms, although he has sought to bring about more single judgments (rather than each lord delivering an opinion).

In the midst of all this was his unsuccessful fight to be elected as Chancellor of Oxford University. He admits to mixed feelings — but his wife Elizabeth was delighted. “She was extremely supportive but desperate for me to lose — it would have meant giving up weekends in the country” (where he likes to walk). He wanted to win, but is not “deeply wounded or anything like that”.

He is on the home stretch — he retires next July — and one or two observers say they detect that he is less interventionist, less directing of his colleagues. The truth, say others, is that the law lords are more vocal, more confident in applying the Human Rights Act and Bingham has less need to steer them. Either way, he has plenty on his plate, including, next year, the appointment of his successor. And for July, a book commissioned from Penguin on the rule of law.

The job, he says, has been immensely satisfying. The law lords may have come in for political flak of late but they have not felt under pressure, political or otherwise, over their decisions. “We see our job as a purely judicial one, to try to get the law right and apply it properly to the facts. I don’t think we spend very much time worrying if our decisions are going to be popular or not.”

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