Mid and East Antrim council has refused a request to help with handling Brexit Protocol checks at Belfast Port following the suspension of P&O ferries in Larne.
Belfast City Council officials asked if council staff at Larne Port could provide administrative assistance for dealing with an expected increase in traffic at the city harbour.
Senior officials in Mid and East Antrim sought the views of party group leaders but opposition was expressed by the DUP, TUV and Ulster Unionists, representing a majority on the council.
Read more: P&O Ferries: Workers at Larne Harbour feel they're living a 'bad dream' after shock redundancies
The local authority subsequently declined the request from their counterparts in Belfast City Council.
It is expected to be another week before P&O ships operate from Larne Port after the ferry company sacked 800 UK staff without any notice.
Protests have been held in Larne and at locations across Britain amid growing anger over the sudden lay-offs.
DUP councillor Gregg McKeen said his opposition to staff assisting Belfast was to do with showing solidarity with P&O workers and because of the party's opposition to the Northern Ireland Protocol.
"We should be standing to support the workers who lost their jobs," he said.
He added: "From my point of view and our party's point of view, I don't want to be doing anything to be supporting the outworkings of the Protocol."
Mr McKeen also said their staff may be needed for redeployment to other roles in their own council in the coming days.
TUV councillor Matthew Armstrong similarly said he was opposed to officials assisting Belfast Port due to solidarity with P&O workers as well as being against the Protocol.
He said: "I certainly wasn't going to take the opportunity to remove staff to help out a neighbouring council with implementing the Protocol."
UUP councillor Keith Turner said his focus was on showing support for staff sacked by P&O Ferries, describing the treatment of its workers as "shameful".
A Belfast City Council spokesman said: "In response to the anticipated increase in traffic through the Port of Belfast following the temporary suspension of P&O ferries into the Port of Larne, Belfast City Council officers approached Mid and East Antrim council about possible assistance that might be provided to staff in Belfast.
"This assistance would be administrative in nature and would not involve relocating staff to Belfast.
"Mid and East Antrim council are unable to facilitate this request in the short term, but as the situation is fluid this will be kept under review."
Mid and East Antrim Borough Council said its party group leaders' forum is a "sounding board" with no decision-making powers, and that declining Belfast council's request was "based on operational need".
A spokesman said: "Council has informed Belfast City Council that, due to operational needs, we are unable to provide assistance.
"This is an unpredictable situation which we are keeping under review and council are working with various stakeholders to try and resume normal business at Larne Port as soon as possible."
Read more: P&O Ferries: Workers at Larne Harbour feel they're living a 'bad dream' after shock redundancies
Read more: P&O Ferries issues statement admitting redundancies have caused "distress"
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