Scottish Renewables, the body that promotes the wind-energy industry, has warned that changes in the law making it easier for anti-turbine protesters to challenge planning decisions will cost jobs and investment in Scotland.

The group was responding to a landmark case concerning a small proposed development in Berwickshire by Wind Direct, where a local householder has been allowed to take Scottish Borders Council to the Court of Session over the erection of two 110m-high turbines less than one kilometre from her house in the conservation village of Cockburnspath.

An amendment to Scots law, which came into effect in March this year following an EU environmental directive, has allowed objector Sally Carroll to obtain a "protective expenses order" (PEO) from Scotland's highest civil court. The order caps her liability at £5000 if the appeal against the decision by the council's local review board fails, instead of the £100,000-plus in legal fees that she would otherwise incur.

Joss Blamire, senior policy manager for Scottish Renewables, warned that the ruling could be used as a "tool to overly delay responsibly developed and well-sited projects" which would create "uncertainty" for developers, disrupting investment and jobs.

The case is also believed to be the first high court challenge to a decision by a local review board, the body that considers appeals of council planning decisions.

Carroll said: "The judge, Lord Drummond Young, acknowledged that to comply with a European directive it must not be prohibitively expensive for an individual to challenge a decision that impacts on their environment, and that includes the cost of getting the PEO in the first place.

"Without this breakthrough I simply could not afford to challenge the council's decision.

"Like many people here in East Berwickshire, I feel we are under siege from developers. We are fed up having wind farms dumped here. Local and national government should be answerable to the electorate for their decisions, but until now it has been impossible for people like me to challenge them."

Neil Collar, head of planning law at Brodies LLP, said that the court's award was "significant", but was unlikely to radically affect the balance of power between promoters of onshore wind farms, and Scotland's increasingly vocal and organised anti-turbine protestors.

He said: "Objectors still face an uphill struggle to get planning decisions quashed by the courts, because the grounds of challenge are limited to points of law. For an appeal to succeed, it has to be shown that a legal error was made in granting planning approval.

"Research undertaken by Brodies shows that only one in four challenges are successful. While there might be more challenges in the future, objectors are no more likely to win. Nevertheless, legal challenges cause uncertainty and delay, which is a concern for developers and it is of some reassurance that consideration is being given to procedural mechanisms to filter out weak cases."

Joss Blamire, senior policy manager for Scottish Renewables, said: "We recognise that there can be disagreements and the introduction of the PEOs should ensure access to the courts are not prohibitively expensive.

"We would be concerned if these kinds of orders were used as a tool to overly delay responsibly developed and well-sited projects.

"Ultimately, this kind of delay in the planning system could create increased uncertainty for developers and see local areas losing out on investment, community benefit funding, employment opportunities and importantly, any contribution towards tackling climate change."

The new setback for the wind industry follows proposed new rules on wind-farm applications on "wild land", and within 2.5km of cities, towns and villages.

The proposal has been vehemently opposed by Scottish Renewables, which last month said the "broad brush" proposals were out of tune with "good public support" for wind-farm development in rural Scotland.

Chief executive Niall Stuart said: "These new rules could put the brakes on at least 1.4 gigawatts of onshore wind projects - threatening £2 billion of investment, along with much-needed job opportunities."