Greater Manchester Police may have to send some of its officers to Kent in the event of a no deal Brexit.
Deputy mayor for crime and policing, Beverley Hughes said during a press conference that the force had been asked to offer 'mutual aid' if the situation warranted it.
The deadline for a deal on Brexit set by the European Parliament passed with no sign of progress and may now go on until December 31 - when the transition period is due to end.
Dept Hughes expressed concerns over the failure to get a deal, and what this could mean for security measures and policing in the UK.
"I understand the focus on getting a trade deal," she told the press conference.
"But the European Commissions have made it clear that if we don't get a trade deal then we won't get agreement on continuing the reciprocal arrangements around security measures.
"It is absolutely imperative and it has been difficult to get air time to help people understand how important that is."
"It is crucial both economically and in terms of security that we do get a deal," she added.
The deputy mayor was asked about what she made of scenes of queueing lorries at the Port of Dover, and what preparations were being made in Greater Manchester to mitigate the disruption come January.
On Sunday, the Port of Dover and Eurotunnel closed to traffic as a number of countries imposed a travel ban on the UK.
The ban was introduced over fears of a new fast-spreading strain of coronavirus in London and the South East, but has also raised concerns about the potential impact of a no-deal Brexit.
"I look at those scenes down in Kent and Dover with horror - it looks absolutely chaotic," Bev Hughes said.
"There will be an impact on that here because we have been asked, as other police forces have, to offer mutual aid - that is to send our officers down there to help with that situation should it be warranted.
"That creates other pressures for us up here."
Andy Burnham reiterated those concerns, and urged for 'common sense to prevail' over the coming days.
Cabinet minister Michael Gove has suggested the two sides could sign a series of “mini-deals” to prevent chaos if talks end in failure.
He previously warned a deal is 'realistically' unlikely to be signed off until after Christmas.
"There are certainly security concerns when it comes to Brexit but we have all looked at the scenes around Dover and it's of great concern," Mr Burnham said.
"The current pressure is linked to the new strain of the virus but you can't disentangle it from Brexit either."
Mr Burnham said that he and other health leaders had also expressed concerns about vaccine deliveries, which are coming in from Belgium.
"I think it all points to a sensible resolution of the Brexit negotiations," he added.
"We need the agreement of a deal that will allow us to bring a degree of stability and continuity to our arrangements with our European partners.
"Life is complicated enough right now without making it even harder. To throw in a no deal situation I think would be reckless."
