The campaign, launched last week by Red Savannah chief executive George Morgan-Grenville, has sparked fierce debate over the merits of the policy, which is due to come into force on Monday (8 June).

Morgan-Grenville wrote to home secretary Priti Patel on behalf of 70 backers late last week, with the measures then set to be laid before MPs upon their return to the Commons on Tuesday (2 June).

This was pushed back to Wednesday (3 June) giving Patel and transport secretary Grant Shapps time to defend the policy in a Daily Telegraph editorial, which made oblique reference to the campaign – by then backed by more than 300.

Paul Charles, founder of the PC Agency and one of the coordinators of the campaign, confirmed on Thursday (4 June) more than 500 companies had now written in support of the effort and endorsing its call to "quash quarantine".

Following Patel’s Commons address, in which she confirmed the quarantine proposals would go ahead while offering to host a "roundtable" with representatives from the travel sector on Thursday, Morgan-Grenville said it was clear government had "neither listened to the concerns of the travel industry, nor seemed unduly bothered by them".

“We are none the wiser as to the science behind the rationale for quarantine, and we still don’t know what the ’enhanced border measures’ in March actually achieved," he said. "But what we do know is that ’Global Britain’ is shut for business.

“It is the wrong policy that is going to cause untold misery for hundreds of thousands of people who will now very likely be made redundant. The government are responsible for lives and livelihoods.

"Has the home secretary thought about what the loss of livelihood is going to do to the lives of so many people across the UK travel and hospitality industry? She must now take responsibility for the consequences.”