Exports of Scottish seafood from smaller companies are to be halted for a further five days by the transport company that handles most of the trade.
DFDS stopped groupage exports last week after delays in getting new paperwork for EU border posts in France.
That was due to have resumed now but the company has told customers it will not begin again until next Monday.
Paperwork will then have to be approved before consignments can be sent to DFDS's warehouse in South Lanarkshire.
That vast, chilled site in Larkhall is where many smaller batches of seafood are consolidated into truckloads.
It is then transported to the English Channel ports and on to customs and the large market in Boulogne-sur-Mer.
Delays are reported by industry sources to have meant a sharp drop in exports - in one company's case, the normal flow of 100 tonnes of seafood per week resulted in only 8.5 tonnes being shipped.
Salmon and some other single company truckloads have gone ahead.
That is because the required paperwork - called an Export Health Certificate - is relatively simple for one load from few sources.
More than 10 trucks left Larkhall for export on Tuesday night. A normal night would see about 27 despatched.
Prime Minister Boris Johnson told a committee of MPs fishing businesses would be compensated for what he described as "temporary frustrations".
Where truckloads might have many species of fish, landed by different boats, at different ports, and sent to market by different wholesalers, that has made for much more complicated groupage paperwork.
One consignment without the right paperwork can hold up all the others.
Last week, as exporters realised the demands of the new regime, it took as long as eight hours for a qualified veterinary inspector to sign off the truck load.
Some loads did not have the paperwork required, and had to be redirected into the UK market.
A statement from DFDS on Wednesday said computer systems had been adjusted and extra employees trained to help customers with accurate customs declarations.
The Groupage Export Service will start again on Monday 18 January, but it will not be an overnight service, Instead, it will take two nights from arrival at Larkhall to reaching the French market - known as "day one for day three".
DFDS acknowledged the "painful" effect of the interruption to exports on its customers.
It added: "We will continue to make every effort to assist those requiring support. By working together we aim to have a robust service running very soon again."
In Parliament on Wednesday, Prime Minister Boris Johnson was challenged by SNP Westminster leader Ian Blackford on the damage being done to the seafood sector in Scotland.
The issue also arose following a statement in the Commons by Michael Gove, the UK cabinet secretary taking the lead on new trading arrangements with the European Union.
He acknowledged the government has a lot to do to ensure the steady flow of goods into Northern Ireland as well as into Europe.
Mr Gove said: "We are also working closely with industry to address specific problems of moving mixed food loads from Great Britain to Northern Ireland through the process known as groupage.
"In the coming days, the government will issue new guidance on the practical mitigations that have been developed with industry to enable this important practice to continue and to support hauliers and suppliers."
He went on to say these would also apply to exports across the English Channel.
Meanwhile the prime minister told a committee of MPs: "Insofar as there are delays caused by a variety of problems, we will compensate those fishing businesses."
Jimmy Buchan, of the Scottish Seafood Association, welcomed Mr Johnson's "unequivocal promise" and said he looked forward to engaging with the government on the detail of the package.