Institutional investors are urging Spanish infrastructure group Ferrovial to re-route a Polish infrastructure project they claim endangers local wildlife.

The Polish government, which commissioned the Via Baltica by-pass project, is currently before the European Court of Justice facing allegations the project failed to ensure wildlife habitats in an EU Special Protection Area.

Ferrovial denies responsibility for the alleged breaches and claims responsibility lies with the Polish state, blaming a "deficient environmental evaluation process".

"Under the European directive, both the investor of the project and the actual builder may be liable for environmental damage," said spokesman Luis Alonso.

"Under Polish law, the builder cannot be liable if he operates in accordance with the administrative permit and the decisions of the Polish environmental authorities," he added.

However, GES, a Swedish socially responsible investment (SRI) consultancy that advises investors with €220bn in assets under management, said it was optimistic ‘engagement’ with Ferrovial on the issue would be successful.

Managing director Magnus Furugård said violations of international norms pose a considerable reputational and financial risk to companies and their investors.

He told IPE Real Estate "to a large extent" pension funds in northern Europe were already factoring environmental concerns into risk assessments of potential acquisitions.

"It isn’t so much pressure as motivation," he said.

"Many pension funds today want to explain that they’re responsible investors. Initiatives from the UN and large asset managers has fuelled the trend even further. Some pension funds see environmental responsibility as part of the [asset’s] value.

"In this kind of project, it’s the largest risk they have," he added. "It’s also top of the agendas of the public and politicians in Europe."

Ferrovial’s Alonso acknowledged environmental issues represented a growing source of reputational risk for the firm, at the same time as it put up for sale its share of a property partnership it acquired last year with its £16.3bn (€24bn) acquisition of UK airport operator BAA.

"Investors are interested in environmental issues as well as in other key issues of the business," he said. "The environmental area is a key piece of our politics in corporate responsibility. We have a very strong control of environmental risks," he added.