Northern Ireland's Agriculture Minister has halted construction of permanent inspection facilities for post-Brexit checks on agri-food goods arriving from Great Britain.
DUP minister Gordon Lyons has also stopped further recruitment of inspection staff for the port facilities and ordered an end to charges levied at the ports on traders bringing goods from GB into Northern Ireland.
Ongoing Irish Sea trade checks, which are taking place at existing repurposed port buildings and other temporary facilities, will continue.
Mr Lyons's decision relates to ongoing work on new purpose-built inspection facilities at ports like Belfast and Larne.
Mr Lyons told the PA news agency: "I've just let executive colleagues know that today I instructed my department to halt work on a range of issues relating to work at the ports.
"This is in and around a number of areas, first of all further infrastructure, any further infrastructure builds; the additional recruitment of staff; and also the charging at the ports."
The decisions come amid the ongoing controversy over disruption caused by the Northern Ireland Protocol, which governs Irish Sea trade post-Brexit.
Unionists are angry at the protocol's requirement for checks on many goods entering Northern Ireland from the rest of the UK.
They claim it has driven an economic wedge between the region and Great Britain, and has undermined the Union as a result.
Mr Lyons said his move was in response to the "practical difficulties" caused by the Protocol.
He cited uncertainty over the movement of goods when grace periods currently limiting protocol bureaucracy end at the start of April.
He said: "We don't know what the movement of retail goods from Great Britain into Northern Ireland is going to look like, we don't have the support in place through the digital assistance scheme yet either, and all of the SPS (sanitary and phytosanitary) issues around the end of the grace period are just so uncertain and it's real nightmare for us and it's going to be causing us an awful lot of problems."
Mr Lyons's Department of Agriculture, Environment and Rural Affairs has been fulfilling the UK Government's legal duty to construct the facilities under th terms of the Brexit Withdrawal Agreement's Northern Ireland Protocol.
