Creating a huge "emergency truck park" in Kent for up to 10,000 vehicles waiting to travel to Europe would be "bad news for British companies that have been through a terrible time," said Labor's Rachel Reeves .
Ms. Reeves said the country is "staring at the barrel of Brexit," only five months from the end of the transition period.
The Labor Brexit spokeswoman spoke to the PA news agency in front of a 27-hectare site near Ashford that was recently taken over by the government.
There were concerns that the country could be used as an "emergency truck park" for thousands of vehicles waiting to travel to continental Europe, and as border controls.
Construction work with heavy excavators was already underway behind Ms. Reeves.
The country is next to the busy M20, a key route for trucks that drive to and from the port of Dover and Europe.
Ms. Reeves said Thursday, "The government said this was the easiest trade agreement that could ever be negotiated.
"We are four years later (after the referendum) and we don't have a trade agreement yet.
"The Prime Minister said only a few months ago that a trade agreement will be concluded by the end of July.
"Well, we are now at the end of July, we have no trade agreement, we only have a blueprint for a huge truck park in the middle of Kent.
"So this is very different from what we were only promised in the parliamentary elections last December."
She warned that companies were heading for "serious friction with our trade with our closest neighbors."
She added: "It is bad news for UK companies that have been through terrible times in the past few months."
Carla Hopkins, who lives nearby, met Ms. Reeves on Thursday morning and told her that the residents had no warning about the plans.
She said, "We were told nothing. It was sneaky.
"At first we knew that the sign a few weeks ago read that the footpath was closed."
She said she was concerned about the pollution that "concrete monstrosity" would cause and the loss of another piece of the landscape forever.
Richard Lavender, President of the Kent Invicta Chamber of Commerce, said it must "be" from a business perspective due to its proximity to the freeway and Junction 10A.
He added: “Somewhere we need three or four of them across Kent.
“The problem is that our infrastructure is only closed if there is a fishing strike in Calais, no cross-channel ferries and the like, and we come to a standstill in this county every time. That's why companies say to me: 'Solve Solve the problem and get these trucks off the road. "