The European Union has observed the practice of daylight saving time since 2001. But the European Parliament voted in March in favour of scrapping the half-yearly time changes from 2021.

That measure now requires the support of 55 percent of EU member states representing at least 65 percent of its population to become law.

But if a post-Brexit Britain then retained daylight saving time, the Republic of Ireland and the British region of Northern Ireland would be in different time zones for half the year.

That would be "profoundly serious... creating significant unnecessary problems for people living on the border and for the all-island economy," Justice Minister Charlie Flanagan said a government meeting agreed to oppose the EU change.