Further details on the plans for quarantine hotels will be released next week - not today as the prime minister had suggested.
Boris Johnson announced at a Downing Street news conference on Wednesday that the health secretary would be detailing further rules for travellers arriving in England in a statement to the Commons on Thursday.
However, Downing Street issued a statement saying no announcements on the issue will be made today.
And speaking to Sky News, vaccines minister Nadhim Zahawi said: "The quarantine is being operationalised and will play a part of this overall strategy and the secretary of state for health (Matt Hancock) will detail next week the operational elements of that policy."
Ministers have been under fire for failing to come forward with details as to when the scheme will come into effect, a week after it was first announced.
Rules around international travel were tightened last month, with all travellers having to self-isolate for 10 days when they arrive in the UK.
Quarantine hotels will be used for people arriving from countries from where non-residents or nationals are already banned from entering the UK.
This "red list" includes all of South America, southern Africa, Portugal and the United Arab Emirates.
Passengers will be met at airports and transported directly to hotels, where they will self-isolate for 10 days.
But Best Western chief executive Rob Paterson said he is still "yet to understand exactly what protocols are required of the hotels".
Speaking to Radio 4's Today programme, he said: "I think in any normal company if you went out and announced a programme nationally, and you hadn't thought about how you were going to plan that, and you hadn't spoken to the people involved, I'm not sure I'd have a job if I did that in my company.
"To this day we simply haven't heard anything, despite multiple offers.
"We've got all these contacts in other countries that have already rolled this out for some time. They could offer some really valuable support and we're just simply kept in the dark."
Labour MP Yvette Cooper, who chairs the Home Affairs Select Committee, said it was troubling that the government had not yet spoken to major hotel chains about the plan.
She told the same programme: "We've always been warned about both second waves and new variants; the work should have been done a long time ago.
"The problem is, of course, as long as we're waiting, not just for this system but for stronger measures, we know that the system isn't working at the moment.
"We can see that because the South Africa variant is spreading across the country. That's the evidence that too many cases are getting into the country, then spreading in the country."