A host of measures to prepare the UK border for Brexit may not be ready for a no-deal scenario, a watchdog has warned.
The Government faces a race against time to replace critical IT systems, boost Border Force staffing levels and build new infrastructure to track goods, according to the National Audit Office.
It said effective management of the border is "fundamentally important" and highlighted the potential for crime gangs to exploit any gaps.
Sir Amyas Morse, the head of the NAO, said: "Government has openly accepted the border will be sub-optimal if there is no deal with the EU on 29 March 2019.
"It is not clear what sub-optimal means in practice, or how long this will last.
"But what is clear is that businesses and individuals who are reliant on the border running smoothly will pay the price."
In a wide-ranging report, the watchdog found political uncertainty and delays in negotiations have hampered the effectiveness of departments’ border planning and delivery.
It said many of the changes needed under a “no deal scenario” may not be ready for when the UK formally departs the EU on March 29.
In particular, the NAO detailed how:
- 11 out of 12 major projects to replace or change key border systems were, as of last month, assessed as being at risk of not being delivered on time and to “acceptable quality”
- New infrastructure to track and physically examine goods cannot be built before March
- Additional resources required to operate the border may not be ready
- Border Force intends to recruit 581 additional operational staff, and increase numbers over the months following EU exit
However, it said the agency acknowledges there is a "significant risk" that it will not deploy all the staff it plans to recruit by March 29, 2019.
Significant issues will need addressing to avoid a long period of “sub-optimal border functioning” following a no-deal departure, according to the assessment.
It said: "Government’s assumption that the risks will not change materially on day one is reasonable in the short-term but organised criminals and others are likely to be quick to exploit any perceived weaknesses or gaps in the enforcement regime.
"This, combined with the UK’s potential loss of access to EU security, law enforcement and criminal justice tools, could create security weaknesses which the Government would need to address urgently."
The NAO also concluded that businesses do not have enough time to make the changes needed if the UK leaves the EU without a deal, and warned that the most complex issues relating to the movement of goods at the border, such as arrangements to apply at the Northern Ireland and Ireland border, still need to be resolved.
The issue of future border arrangements has been one of the most closely scrutinised aspects of the Brexit negotiations.
If a deal is reached, under the terms of the draft withdrawal agreement published earlier this year, there would be an implementation period running until the end of 2020.
That scenario could involve "significant work", the NAO report said, adding: "However, the scale of this change will be nowhere near that required if the UK and the EU cannot reach an agreement."
Meg Hillier, who chairs the Commons Public Accounts Committee, said: "The NAO’s latest work on the UK border shows the slow progress made on preparations.
"Infrastructure at our borders will not be in place in the event of a no-deal and there is a real danger that systems will not be ready."
A Government spokeswoman said: "Extensive work to prepare for a no-deal has been well under way for almost two years and we have robust plans in place to ensure the border continues to operate from the day we leave.
"Future IT systems and infrastructure are already being built and, as they do today, HMRC will continue to apply an automated, risk-based approach to customs checks.
"This means any increase in the number of checks will be kept to a minimum.
"We will always ensure we have the necessary resources to keep the border secure, and that’s why we’re recruiting approximately 600 Border Force officers to prepare for the day we leave the EU, in addition to the 300 officers which will be deployed by the end of the year."