In the first significant test for border disruption, the UK Department for Transport's (DfT) experiment, named "Operation Brock", saw almost 100 lorries from the disused Manston Airport, in Kent, on a 20-mile journey to Dover - Europe's busiest roll-on roll-off ferry port - at around 8am, the Evening Standard reports.
The exercise, known as Operation Brock, is turning the Manston Airport site into a mass holding bay for heavy goods trucks, to ease congestion on major highways to British ports such as Dover, southern England.
A transport ministry spokeswoman said 89 trucks were taking part in Monday's exercise at a cost of $700 per driver or £48,950 for the whole fleet.
"It beggars belief that we are spending tens of thousands of pounds of taxpayers' money to create a traffic jam for a dead-end Brexit".
However, the EU Commission has said there will be no renegotiation.
On Twitter, he said: "Routing lorries via Manston is not the answer".
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.
Layla Moran, a Liberal Democrat lawmaker who wants another referendum on European Union membership, said the truck journey would not convince the European Union that Britain was ready for no deal.
Liberal Democrat MP Layla Moran, of the anti-Brexit Best For Britain campaign, said it was a "taxpayer-funded farce" while Shadow Transport Secretary Andy McDonald said it was "beyond parody".
Amid the ongoing uncertainty surrounding Britain's high-drama Brexit process, fears that the country could exit the 28-member European Union bloc without a deal on the terms of its departure have continued to escalate.
But pro-Europeans fear Britain's exit will hammer the economy and undermine the West as it grapples with Donald Trump's unpredictable USA presidency and growing assertiveness from Russian Federation and China. "All back in the hold area at Manston Airport waiting for the second run".
It "should have been done nine months ago and repeatedly stress tested", he tweeted on Monday morning. "At this late stage it looks like window dressing". The EU has signalled it may try to allay the fears of May's critics but will not renegotiate the deal.
The letter has been backed by business organisations such as the Confederation of British Industry, manufacturers' organisation EEF, the Federation of Small Businesses and the Society of Motor Manufacturers and Traders.
"Don't' let the search for the ideal become the enemy of the good", May said.
Last month, May pulled a vote on the brokered withdrawal agreement, settled on in November after more than a year of back-and-forth negotiations between London and Brussels, acknowledging it would have been roundly rejected by the UK's lower chamber House of Commons.
But parliamentary opposition to her deal remains fierce, with the main sticking point being the safety net "backstop" measure - which would guarantee no hard border is erected on the island of Ireland in the event that post-Brexit trade negotiations between the United Kingdom and the bloc prove unsuccessful.