Lough Beg swans are at the heart of the A6 battle

Chris Murphy confirmed in the High Court he will take fresh steps to secure a prohibition on preliminary work to build a section of the A6 Belfast to Derry upgrade close to wetland where migratory birds forage.

He also told a judge that he lacks the financial means to pay for the unsuccessful challenge - even though his liability was capped at £5,000 under a heavily reduced protective costs order.

Mr Murphy said: "I have got no money, that wouldn't be hard to prove."

The ornithologist took legal action in an attempt to halt construction of the part of the road near Mossbawn, Co Derry - the childhood home of the former Nobel laureate poet.

The route was identified following a public inquiry nearly a decade ago.

With commuters regularly facing rush-hour gridlock, former Infrastructure Minister Chris Hazzard gave the green light to the scheme last year in a bid to significantly improve a major transport corridor.

Proceedings centred on ecological checks made to potential disturbance to whooper swans on Lough Neagh and Lough Beg from the disputed Toome to Castledawson stretch.

Mr Murphy, who represented himself, claimed the plans will cause irreparable harm to an area worthy of word heritage status.

In impassioned submissions he compared building a road through the site to cutting away at a Rembrandt masterpiece.

Further assessments have been carried out since the department first made checks on the presence of nesting birds, badgers and bats.

But the court had to determine whether these actions were part of a fulfilment of obligations under the relevant habitats directive.

Last week Mrs Justice Keegan ruled that the decision making process was lawful and rational.

Returning to the case today, she gave Mr Murphy until April 25 to confirm if he intends to appeal her decision.

Counsel for the department said he was instructed to seek costs of the judicial review, which were previously capped at £5,000.

Making the order, the judge acknowledged Mr Murphy's financial circumstances and stressed it was a limited amount compared to the "phenomenally expensive" nature of the case.

The court also heard that the department has not yet entered into any contract, but may have to begin cabling and other preparatory work.

Mrs Justice Keegan declined a request to impose an injunction, telling the environmentalist it could form part of any appeal process.

Mr Murphy responded: "I will work on the injunction, which I will now seek."