Recently some of the biggest names in law have been getting together in an office on Chancery Lane to discuss weighty legal issues until late in the evening. "It's a bit like being called up to play for England," says criminal barrister John Cooper QC, one of 14 members of the invitation-only legal thinktank Halsbury's Law Exchange – set up last summer by legal publisher LexisNexis.

It is the latest example of a slow-burning trend among practising lawyers to involve themselves in policy, dating back to 1992 when City law firm Clifford Chance launched its "public policy unit". The move was followed by rival DLA Piper – whose EU public affairs team is led by the deputy PM Nick Clegg's wife, Miriam Gonzalez – before last year Allen & Overy unveiled a Global Law Intelligence Unit, concerned with the development of international commercial law.

As you might expect from bodies closely affiliated to commercial organisations, much of their output is self-serving. Clifford Chance's tracking of the recent European court case over the use of gender in underwriting premiums, for example, was carried out to protect the large insurance companies it works for.

But the firm's advocacy regarding the newly introduced immigration cap had wider value. As did Allen & Overy's report in September on the business-friendliness of various foreign jurisdictions, making a useful contribution to the promotion of greater uniformity in international commercial law as well as impressing clients.

Meanwhile, Halsbury's paper on the potential legal problems arising from the government's new employee vetting and barring scheme, which will be published next week, promises an interesting read given the range of input it has received.

Even at their best, though, these self-styled "thought leaders" function at a far more superficial level than the academic lawyers behind, say, the Jackson reforms. In his policy brief on civil litigation funding, which was heavily drawn upon in Lord Justice Jackson's review of the civil litigation costs structure, Professor Chris Hodges of Oxford University's Centre for Socio-Legal Studies devoted two years to examining conditional fee arrangements in 35 European countries to a level of detail that a lawyer practising full-time couldn't hope to match. "We research, we think, we talk. That's our job," he says.

One of the most frequently voiced complaints by academics is that their practitioner counterparts don't appreciate how much this sort of painstaking research informs not just policy, but the way the profession behaves – driving everything from the regulation of lawyers to law firms' diversity programmes. According to Dr Louise Ashley, a research fellow at Cass Business School's Centre for Professional Service Firms, practising lawyers often fail to realise that diversity itself is a construct hotly debated by academics – an oversight that limits their ability to influence discussions about its practical application. "It's helpful to know about the origins of the terminology when you're developing new ideas in practice," she says.

Perhaps this tendency to overlook the contribution of academia explains why there is just one full-time academic lawyer (Professor Ian Smith) on Halsbury's Law Exchange – something of a surprise given the current keenness among universities to engage with practitioners in the wake of new research funding criteria demanding they prove the practical relevance of their work.

One law firm that has shown a willingness to engage with its counterparts at universities is personal injury outfit Thompsons. Rather than get directly involved in arguments over the Jackson reforms, the firm funded a team of academics to produce a paper against the proposals.

Roderick Bagshaw, an Oxford University law lecturer who was part of the 11-strong group (selected on the basis that they were known to broadly share Thompson's anti-Jackson views), admires the firm's tactics, even though they were to prove unsuccessful.

"Lawyers who earn money from no-win no-fee arrangements would obviously object to Jackson, limiting the impact of their arguments against it. But when those who wouldn't be directly affected produce a paper on the issue people are more likely to listen," he says.

Thompsons may have lost that particular battle, but expect similar ventures in the future as the tentative advances between the ivory tower-dwellers and those on the frontline continue.

Alex Aldridge is a freelance journalist who writes about law and education