A cross-party committee of MPs has warned Prime Minister Theresa May it is “essential” that the stability of Northern Ireland is not jeopardised by EU withdrawal.
The first report by the Exiting the EU Committee has called for devolved administrations to be “duly involved” in the Brexit process, alongside English regions, and have their views taken into account.
The committee has also called for Mrs May to make clear whether she aims to keep Britain in the European single market and customs union when she publishes her Brexit negotiations plan.
It further insists the prime minister must commit to giving MPs a vote on the final deal which she secures with the remaining 27 members.
The committee has said that Mrs May must publish her plan in the form of a White Paper by mid-February, to give MPs a chance to debate it before negotiations are kicked off by the tabling of Article 50 in March.
The prime minister has signed up to a Labour motion requiring her to publish details of her plans for Brexit before the invocation of Article 50, but has so far given little indication of what it will contain.
The PM - who will deliver a major speech on the post-EU future on Tuesday - has also held back from revealing whether MPs will be granted a vote on the Brexit deal.
The committee - which includes prominent Brexiteers like Michael Gove, John Whittingdale and Dominic Raab, as well as former backers of the Remain campaign – has warned that the task of preparing for Brexit is placing “strain” on departments across government.
Its report stated that managing and implementing the decisions required to prepare for life outside the EU will be a “significant challenge” for the civil service for a matter of years and “may well” require the recruitment of more staff.
The report further said ministers should seek an outline framework of the UK’s future trading relationship with the EU as part of the Article 50 negotiations, with appropriate transitional arrangements to allow trade to continue normally if a deal is not reached in time for the expected Brexit date of 2019.
But it warned that this “will not be in the Government’s gift to deliver”, as the EU may insist on delaying trade talks until after the withdrawal negotiations are over.
It would be “unsatisfactory and potentially damaging” to both the EU and UK if Britain tumbled out of the bloc without a deal when the two-year Article 50 deadline expires, the committee warned.
An abrupt “cliff edge” departure would be “extremely disruptive” and the absence of transitional arrangements could push some businesses to relocate or move investment overseas, it claimed.
The committee argued that the Government should seek to ensure continued access to EU markets for UK financial services providers - whether through the extension of “passporting” rights or an agreement on mutual recognition of regulations.
And it said it was “essential” that co-operation should continue on defence, foreign policy, security, financial crime and counter-terrorism.