A powerful consumer charity has asked for a formal investigation into concerns that Scots are not getting enough access to affordable justice and legal representation.

Which? has sent the Office of Fair Trading (OFT) a "super complaint" to recommend it addresses fears that the current regulation of legal firms is hindering the market, restricting choice and pushing up the price.

The move comes ahead of reforms being introduced south of the border which will allow banks and supermarkets to join forces with law firms and provide legal services.

Following a review by Sir David Clementi, organisations such as Tesco and the RAC should, from 2008, be able to offer legal services alongside sandwiches or roadside assistance. The changes, supported by the OFT, are intended to make the legal profession more responsive to consumer needs.

However, Which? believes the Law Society of Scotland, the Faculty of Advocates and the Scottish Executive have all demonstrated no appetite for exploring, let alone implementing, alternative structures.

Areas such as conveyancing, litigation in court and obtaining confirmation in executries must be undertaken by solicitors in Scotland. Other services such as will-writing can be done by non-solicitors, but that is usually not the case.

Which?, at the vanguard of revolutionising provision of legal services in England, is turning its attention to Scotland, which it believes is pushing up prices and limiting access for customers.

The OFT has 30 days to consider the super complaint and decide whether to investigate.

A Which? spokeswoman said: "People cannot instruct advocates directly and have to employ a solicitor to do so. We would want to see an independent body created to protect consumers in Scotland in relation to legal services."

Following moves to liberalise the regulations on legal firms south of the border, HBOS, which has two million customers, launched a new service offering "everyday legal products" to customers at what it claims will be considerably lower fees than those offered by high-street solicitors.

The service is being rolled out through the bank's Halifax arm in England and Wales. However, Joel Ripley, head of Halifax Legal Solutions, said last year there are plans to extend it to Scotland.

The Halifax service, which will include discounted conveyancing, will preparation and a 24-hour legal helpline, is also set to provide access to a website where customers can prepare their own documents, including tenancy agreements and letters of complaints about faulty goods. These will be reviewed by qualified lawyers.

Conveyancing in England and Wales will be done by HammondsDirect. In Scotland, it would be undertaken by a firm north of the border. Customers will pay an annual membership fee of £89 which will give them free access to the helpline.

John Campbell, QC, of the Oracle Chambers, said: "The Which? super complaint poses important questions for the way law is practised in Scotland, and opens up the potential for a much more open market in the provision of legal services. It should be welcomed by lawyers as a whole, and by the executive.

"Since these ideas appear to have been embraced south of the border, it is to be hoped the new administration will realise the twin goals of increased competitiveness among lawyers.

"This complaint takes a long, hard look at professional business structures, and finds that simple changes would generally introduce efficiencies, lower costs, and benefit consumer choice.

"Lawyers should look on these ideas as a challenge and an opportunity, not as an attack on their institutions."

Scotland's lawyers have been split on the Clementi review. Some have threatened to move their "brass plaques" south to help them find outside sources of capital and hire non-lawyers for simple jobs.

Others are far from enthusiastic about the prospect of English-style reforms north of the border. The Law Society of Scotland has stressed what it sees as the risks of allowing other businesses to own law firms. What, it asked, if crime organisations take over all the lawyers in a town?