Northern Ireland is badly prepared for Brexit, with businesses here still unclear about the new arrangements after the transition period ends in December, according to a new report.
The report by the Northern Ireland Affairs Committee claims the Government has shown a lack of understanding and an overly political approach to post-Brexit trading arrangements in Northern Ireland, leaving businesses in the dark.
Northern Ireland Retail Consortium director Aodhan Connolly said it was "reflective of the mood" among businesses here. He said: "There is concern and frustration that we are just over five months from the end of the transition period and there is still not the clarity and detail that we need."
The report, which looks at the element of the Brexit Withdrawal Agreement that will see Northern Ireland operate under different trading rules to the rest of the UK, questions the Government's claim that companies in here will have unfettered access to the market in Great Britain from 2021 onwards.
Under the terms of the protocol, which is designed to avoid border checks on the island of Ireland, Northern Ireland will be a part of the UK's customs territory but will still follow EU customs law and administer the bloc's customs rules at its ports.
The region will also follow EU single market regulations.
The Government has acknowledged this will mean more regulatory checks on some goods entering Northern Ireland from the rest of the UK, with the expansion of infrastructure to carry out sanitary and phytosanitary (SPS) screening of animals and food products which sits contrary to its claims that Northern Ireland will have frictionless access to GB goods.
The committee, which is made up of Conservative, Labour, SDLP, Alliance and DUP MPs, called on ministers to provide more detail to businesses on trading arrangements by October 1.
Committee chairman Simon Hoare said: "Those trading across the Irish Sea have been told to prepare without knowing what to prepare for.
"It's now time for them to get that clarity, and they must have it by October 1. If not, business will not have time to prepare for the realistic prospect of friction and delays to products moving between Great Britain and Northern Ireland.
"This will increase their costs, with an accompanying increase in the cost of living.
"It would put Northern Ireland at a competitive disadvantage compared with the rest of the UK and would damage business confidence at a time when it has seldom been lower."
Mr Connolly agreed: "We have always argued that it is necessary for unfettered access from NI to both the EU and GB markets to allow us to continue to provide NI and GB households with choice and affordability.
"That is not what we have at the moment.
"We need the UK Government to be ambitious in asking for a certified supply chain solution that would remove friction for goods destined for retailers' shelves which account for 70% of the value of all GB-NI movements."
Ann McGregor, NI Chamber of Commerce chief executive, said the overriding concern was the lack of time for smaller businesses and their intermediaries to react to any new systems that will be put in place.
She said: "Some of the larger companies can react quicker but the majority of smaller companies aren't fully informed.
"We facilitate trade documentation and provide customs training but we are concerned, from a practical perspective, how companies and their intermediaries are able to deal with this in the timeline now available particularly as HMRC don't have the computer system they're proposing to use tested."
Sinn Fein Foyle MLA Martina Anderson, speaking after a party delegation met the Chamber of Commerce in Derry, said members in the North West feel "unprepared and uninformed" about Brexit.