The Government has launched a campaign reminding firms to ensure they are not caught out by trade rules ahead of the January 1 deadline.

But the British Chambers of Commerce (BCC) said many firms are facing a string unanswered questions about the changes.

The campaign, entitled Time Is Running Out, follows the Government declaring official negotiations over a trade deal as over without a deal.

Prime Minister Boris Johnson said the UK should prepare for what he described as Australia-style terms, although Cabinet Secretary Michael Gove told the BBC agreement could still be reached - if the EU was ready to change its position.

Among the steps the Government is calling on businesses to take are being ready for changed customer procedures, checking on visa or work permit requirements, preparing for the new immigration system, checking qualifications remain valid to provide services within the EU and ensuring personal data can still be received from European countries.

HMRC is also writing to 200,000 firms to set out new rules.

A statement from the BCC said: "Facing the triple threat of a resurgent coronavirus, tightening restrictions and a disorderly end to the transition period, it is little wonder businesses are struggling to prepare.

"Many firms will be tired of posturing, cliff edges and deadlines, while others are still grappling with fundamental challenges as a result of the pandemic."

It continued: "More businesses will undoubtedly step up preparations for change over the coming weeks, but many are still facing unanswered Brexit questions that have a big impact on their day to day operations.

"A UK-EU deal is still both possible and critically important. No matter what happens, businesses will have to change. But we need a deal that supports businesses and jobs, and final clarity over what changes they must make."

The Federation of Small Businesses has warned more clarity is needed as they deal with the twin issues of Brexit and the coronavirus.

National chairman Mike Cherry, said: "Not only have small firms been hit by the most severe recession on record over the past six months, they're now 10 weeks out from the end of the transition period with no clear sense of what our future relationship with the EU will look like.

"Many simply don't have the time or money to make adjustments, even if they want and need to.

"And they don't even know what they're preparing for - the Government is essentially saying get ready for a no-deal outcome even though a deal could still happen."

He continued: "More than four years on from the referendum, clarity is needed now more than ever.

"A pro-business, ambitious trade agreement remains the best outcome. The more changes can be phased in over time the better, particularly in the current climate.

"If the Government wants firms to step-up preparations for a new relationship with the EU it needs to make doing so financially viable. At the moment, thousands of small businesses are running on near empty."