A no-deal Brexit could cause a clock conundrum for Belfast, peers have warned, because of European commission plans to end the convention of changing the clocks twice a year.

The move follows research that found the practice was unpopular and will require EU countries to choose to adopt permanent summer or winter time.

It means clocks in Northern Ireland could end up being one hour out from either London or Dublin if Brexit negotiations fail, and Belfast would potentially have to decide whether to align itself with clocks in the Republic of Ireland or the rest of the UK.

If Northern Ireland and Ireland were to operate on different times then this would likely cause significant confusion at the Irish border – the arrangements for which are already one of the biggest stumbling blocks in Brexit negotiations.

Current rules mean every EU state has to switch to summer time on the last Sunday of March and switch back to winter time on the last Sunday of October, but Brussels proposes ending this across the bloc.

A report by a Lords committee warns that if Dublin goes along with this change and “the UK then decided to maintain summertime arrangements, Northern Ireland (assuming the devolved institutions have been re-established) would have to choose between having a one-hour time difference for half the year either with the Republic of Ireland or with the rest of the UK”.

Although the changes are not due to come in until after the intended Brexit date on 29 March next year, the UK may have to adopt the measures during any transition period, peers said, adding that failure to secure an exit agreement could lead rules on the matter in relation to Northern Ireland to “fall away”.

The European commission president, Jean-Claude Juncker, has said millions “believe that in future, summer time should be year-round, and that’s what will happen”. The move requires the support of all EU countries and backing from MEPs to become law.

In its report, peers on the EU internal market sub-committee recommended the House of Lords issue a “reasoned opinion”, a mechanism that allows parliaments to register concerns about proposals. The recommendation will be debated on Wednesday.

Committee chairman Lord Whitty said: “The European commission’s proposal to end seasonal time changes goes beyond its remit and is not in compliance with the principle of subsidiarity.”