Maintaining common environmental standards and robust enforcement across the island of Ireland must be part of any Brexit deal, environmental groups from the Republic and the North have warned.

They will outline their concerns about the consequences of “a hard environmental border” to a European Parliament committee on Tuesday.

More than 650 pieces of EU legislation are critical to conservation of species and habitats on an all-island basis, according to the chair of Northern Ireland Environment Link (NIEL) Patrick Casement, who is to address the parliament’s Committee on Environment, Public Health and Food Safety.

NIEL and its southern counterpart, the Environmental Pillar, will underline “the crucial role played by cross-Border co-operation in effectively addressing biodiversity loss and climate change risks being undermined by a hard Brexit”.

The environmental coalition will recommend that any agreement reached under the Article 50 process must maintain effective cross-Border environmental co-operation and an all-island level playing field post-Brexit.

It has welcomed last month’s resolution from the parliament which stated the Brexit agreement must be “fully consistent” with the areas of co-operation agreed under the Belfast Agreement, including the environment.

A previous resolution on Brexit in April also highlighted the importance of continued adherence to environmental standards.

Leaked memo

A recently leaked memo produced by the Article 50 taskforce that leads the Brexit negotiations on behalf of the EU calls for the UK to “commit to ensuring that a hard Border on the island of Ireland is avoided, including by ensuring no emergence of regulatory divergence from those rules . . . necessary for meaningful North-South co-operation, the all-island economy and the protection of the Good Friday Agreement.”

In the absence of formal oversight by the European Commission and European Court of Justice, a “governance gap” could open in environmental law enforcement in Northern Ireland and result in “environmental dumping” – with standards in the South undercut by weaker implementation North of the Border, Mr Casement will tell the committee.

The coalition has called for Ireland to be seen as a “single bio-geographic unit” as the whole island shares a host of natural assets such as plants, animals, water and air. At a conference in Dundalk earlier this year, MEPs, legal experts and NGOs outlined how any weakening of legislative protection would be the single greatest environmental risk posed by Brexit.

“Cross-Border environmental co-operation as supported by the Good Friday Agreement and common EU rules play a crucial role in effectively protecting our shared natural heritage,” its submission adds. “Our small island forms a single and unique unit in terms of our natural environment and our plant and animal species do not recognise the existence of a Border.”