It has signed an engagement letter with Diamond McCarthy, which has decades of experience in cross-border litigation and international arbitration.
The agreement means expected costs associated with the claim will be fully funded by Diamond McCarthy on a non-recourse basis.
To date, Lansdowne has been advised on its claim by Mantle Law, a London- and United Arab Emirates-based international arbitration law firm with a focus on energy, construction and infrastructure disputes, noted Lansdowne.
Mantle Law and Diamond McCarthy will co-counsel to progress the claim to conclusion, it added.
The gross compensation claim is expected to be at least $100m (€85m) plus interest. In the event of a successful award of about $100m, Lansdowne said it will take between 60pc and 70pc of the proceeds.
“I would like to thank the legal teams that have worked on our case to reach this substantial funding agreement, which will allow us to proceed to seek just compensation for the loss of our Barryroe asset,” said Stephen Boldy, the chief executive of Lansdowne Oil and Gas.
He noted that the company, shares of which are currently suspended, also intends to complete a reverse takeover of an unnamed target in the first quarter of 2026.
The long-delayed report on Ireland’s energy security will ensure that Ireland’s energy insecurity will persist to 2030 and beyond
AIM-listed Lansdowne Oil and Gas owns 20pc of the Barryroe field. It is pursuing action against the Government for not granting permission to develop the prospect. That decision was taken in 2023 by then environment minister Eamon Ryan.
The Barryroe field was discovered in 2012 about 50km off the coast of Cork. It is thought to contain billions of euros worth of oil and gas.
The other 80pc of the field is owned by Larry Goodman’s Barryroe Transition Energy, formerly Barryroe Offshore Energy.
Lansdowne has taken the case against the Government under the Energy Charter Treaty, to which Ireland is a signatory. It provides a mechanism for disputes in the energy sector between investors and governments.
Barryroe Offshore Energy got into financial difficulties after Mr Ryan’s decision in 2023. Mr Goodman later bought the firm out of examinership. He was already a major shareholder in the company and pledged to invest more than €6m in the business.
The government insisted at the time that its decision to refuse permission to develop the prospect was because Mr Ryan was not satisfied with the financial capability of the applicants. Barryroe Offshore Energy said that the government was satisfied with the project from a technical perspective, however.
In 2022, 48pc of energy used in Ireland was derived from imported oil and 31pc from natural gas.
“It is the company’s view that the long-delayed report on Ireland’s energy security has taken a blinkered approach, driven entirely by environmental dogma, and will ensure that Ireland’s energy insecurity will persist to 2030 and beyond,” Lansdowne said last year.