Nigel Dodds, who is also leader of the DUP group of MPs in the House of Commons, said on Radio 4’s Any Questions programme at the weekend that continued co-operation on energy was sensible.
He said: “There are particular areas like energy because our energy market is too small in Northern Ireland and the Republic of Ireland where it makes sense to cooperate: that should continue.”
A single electricity wholesale market has operated across the island of Ireland since 2007.
Dodds was speaking following reports last week that the UK and Irish governments were close to agreeing regulatory convergence, covering areas including agriculture and energy, to maintain smooth trading relationships across the border between the Republic of Ireland and Northern Ireland.
This would be based on a policy of maximum convergence between the standards and regulations in key sectors, like energy.
Leaders of the main political groups in the European Parliament have been briefed that regulatory convergence across Ireland has been included in a draft agreement on the UK’s European Union divorce terms deal, which is being discussed by prime minister Theresa May and EU commissioner Jean-Claude Juncker today (4 December).
The DUP has opposed wider moves to integrate Northern Ireland into the EU’s single market and customs unions because of fears it would weaken the province’s union with the rest of the UK.