Setting off from Manston, 87 trucks drove the 20 miles (32 km) to Dover and then back again. They will repeat the run later on Monday.
"Less than a hundred lorries is a drop in the ocean compared to the more than 10,000 that go to the channel ports every day," said Charlie Elphicke, a Conservative lawmaker for Dover.
"Sending lorries across Kent on a wild goose chase to Manston airport and then to the port of Dover by small and winding, often single track 'A roads' through Kent villages is not the right plan."
Dover has been Britain's most important gateway to Europe since Roman times and the port now handles 17 percent of the United Kingdom's goods trade. Up to 16,000 trucks a day pass through with everything from perishable food to medicines.
Layla Moran, a Liberal Democrat lawmaker who wants another referendum on EU membership, said the truck journey was a farce.
"The idea that creating a fake traffic jam will show the EU we are ready for no deal is just plain stupid," Moran said. "This is a taxpayer-funded farce."
Brexit supporters say that, while there may be some short-term disruption, in the long-term the UK will thrive outside the EU, which they cast as a doomed and excessively bureaucratic project dominated by Germany.
But pro-Europeans fear Britain's exit will hammer the economy and undermine the West as it grapples with Donald Trump's unpredictable U.S. presidency and growing assertiveness from Russia and China.
Monday's 'war game' was mocked on Twitter, with one journalist describing the queue of lorries as "a fake traffic jam ... to show the EU we are ready for no deal".
Facing defeat in parliament last month, May postponed a vote on the withdrawal agreement she negotiated with the EU and pledged to seek further political and legal assurances from the bloc. The EU has signalled it may try to allay the fears of May's critics but will not renegotiate the deal.
May said on Sunday that Britain would be in uncharted territory if her Brexit deal is rejected by parliament. A vote is due around Jan. 15.
"It's still hard to see any upside to Brexit," said Mike Hawes, chief executive of the Society of Motor Manufacturers and Traders (SMMT), which said new car sales in 2018 fell at their fastest rate since the global financial crisis a decade ago.
"Everyone recognises that Brexit is an existential threat to the UK automotive industry and we hope a practical solution will prevail," he said, calling for lawmakers to back May's deal to guarantee a transition period.
In an attempt to prevent the United Kingdom falling out of the EU without a deal, more than 200 lawmakers have signed a letter to May urging her to rule out a no deal exit.
