The ambulance service which covers the North East has drawn up plans in case a no-deal Brexit holds up delivery of new emergency vehicles from Germany.
The North East Ambulance Service (NEAS), which covers an area from Berwick-upon-Tweed to the North Yorkshire border, has placed an order for 44 modified Mercedes vehicles that are converted by a German firm.
These have been bought to replace 31 vehicles coming to the end of their seven-year lifespan, and another 13 ordered for the 100 new paramedics it has recruited to meet new, lower emergency response times.
The order for the emergency response vehicles is due to be completed by the summer, after the date the UK could leave the EU without a deal.
Should no-deal hold up the supply of the new vehicles, NEAS says it will have to extend the life of its current ambulances, something a spokesman said was "not an ideal situation".
NEAS says it takes about nine months from placing an order to having a road-worthy response vehicle, and its financial plans meant it could not speed up the procurement process to bring forward delivery to before the end of this month.
The NEAS spokesman said: "We are expecting to get the first vehicles coming through in April.
"They are converting 44 chassis into ambulances, and that will be spread over the summer months."
While the conversion company said it can still meet the order, the NEAS spokesman said there was uncertainty over the impact a no-deal Brexit would have, if it happened.
The spokesman said emergency response vehicles are usually run for five years as 999 responders, with a final two years being used for urgent care or at events.
Should the new ambulances be delayed, old ones could be "recycled" into 999 use, the spokesman said.
The trust said it has plenty of spare parts and its fleet is serviced every six weeks to keep vehicles in good running order.
An order for non-emergency patient transport vehicles, using Renault chassis converted in the UK, will arrive before the end of March.