Philosopher John Stuart Mill quipped: ‘He who knows only his side of the case knows little of that.’ Reviewing The Assault on Liberty: what went wrong with rights last week, Roger Smith (of Justice) went further.

Amid flattery – and mischievous misrepresentation – he denies there can be more than one approach to human rights (see [2009] Gazette, 19 February, 8).

Yet reasonable people differ. There are competing views. They should be debated, not denied. I argue for preserving Britain’s proud tradition of liberty, inspired by great thinkers, such as Locke, Mill, Berlin, and nurtured since Magna Carta. All governments face pressure to take short-cuts with liberty. But the assault since 1997 is unprecedented: relentless proposals to extend detention without charge, ID cards, the most CCTV and the largest DNA database in the world. Council snoops deploy intrusive surveillance powers for trivial investigations, while the database state is as likely to lose as safeguard our personal information.

This is common ground with Mr Smith. There is a growing consensus that an increasingly arrogant government has eroded bedrock freedoms. The Human Rights Act (HRA) has not stopped it. That is why, contrary to Mr Smith’s insinuation, I favour a Bill of Rights to strengthen protection of our fundamental freedoms. The European convention provides a sensible list – which could be spelt out in greater detail and supplemented (to protect the right to jury trial and give greater emphasis to free speech). As Mr Smith knows – but ignored – I do not support withdrawal from the convention.

However, I am concerned that human rights are being over-spun as all things to all people. Any consensus on British liberties risks being stretched to breaking point, by those who would shoehorn every grievance into the elastic language of rights.

The problem is less the convention than the Strasbourg Court. From the 1970s, the court labelled the convention a ‘living instrument’, a pretext for it to expand – by judicial legislation – the list of rights agreed by state parties. In 2007, more than half the judges had no prior judicial experience before joining the Strasbourg bench. Its case law reflects this mixed judicial calibre, compounded by a continental approach to human rights which is very different from the British liberal tradition.

This ‘communitarian’ approach seeks to answer the Marxist critique of liberty, by tacking on diverse rights to public services – never dreamt of by the drafters of the convention. The ban on torture has been stretched to allow claims to NHS healthcare and state benefits. There are rights to certain protective police services, trumping the delicate balancing of law enforcement priorities against finite resources. The right to a home has been expanded to give environmental rights. And so on.

The HRA increased our exposure to the rights inflation. In practice, UK courts match Strasbourg case law – although not required by the convention – and judges are licensed to rewrite legislation passed by elected law-makers. Now ministers are contemplating whole new brands of economic and social rights.

Liberty-based rights in Britain were traditionally protectors of the individual against the state. Rights are being transformed into providers, inflating the role of – and dependency on – the state. Yet this rights inflation creates uncertainty, undermining the rule of law. Judicial legislation conflicts with democratic accountability. Combined, they have a powerful cultural effect, contributing to the rising compensation culture.

Those advocating a socialist – or social-democratic – approach long ignored such criticism. That may be changing, as hedge funds appeal under the HRA for extra compensation for Northern Rock’s nationalisation, and BAA sues for interference with property rights having been ruled in abuse of its market dominance as an airport operator. Even human rights lawyers – like Afua Hirsch – are now questioning ‘something deeply counter-intuitive about this incarnation of human rights’.

A Bill of Rights could strengthen core freedoms, insulate the UK from some of the unpredictable case law from Strasbourg and remedy flaws in the HRA. The merits of the liberty-based approach to rights – against the socialist model surreptitiously emerging – should be debated. But Mr Smith denies there is any debate to be had. In doing so, he risks a passing resemblance to the intolerant – but illusory – conservative conspiracy he rails against.

Dominic Raab is the author of The Assault on Liberty. A legal adviser at the Foreign and Commonwealth Office between 2000 and 2006, he is chief of staff to the shadow justice secretary. The views are personal to the author.