Boris Johnson's Government has put aside more than £2 billion to spend on no-deal Brexit preparations as the October 31 deadline approaches.
Chancellor Sajid Javid said the money will ensure the UK is ready to leave the European Union "deal or no deal.”
The funding includes £1.1 billion for departments and the devolved administrations to spend immediately, with a further £1 billion in reserve.
The Treasury has now made £6.3 billion available to prepare for Brexit, including £4.2 billion this financial year alone.
As part of the new funding, £344 million has been designated for border and customs operations, while £434 million has been earmarked to ensure vital medicines are available.
A total of £108 million will help to support businesses, while £138 million will find a public information campaign, information for Britons living abroad and support for areas including Northern Ireland.
Measures include 500 new Border Force officers, support for passport processing, improved infrastructure at ports and extra cash for Operation Brock - the plan to cope with traffic chaos in Kent.
Supplies of medicines could be hit by disruption in the event of a no-deal Brexit, so mitigation plans include increased freight capacity, warehousing and stockpiling.
Mr Javid's announcement, soon after entering the Treasury under Mr Johnson, will be seen as a break from Philip Hammond's era.
The former chancellor was accused by Brexiteers of being reluctant to release cash to prepare for a no-deal exit.
A Whitehall source said: “It really represents a shift in tone for the Treasury as a department.
"All departments that asked for money for no deal got it, this was a very expedited process."
Mr Javid added: "With 92 days until the UK leaves the European Union it's vital that we intensify our planning to ensure we are ready.
"We want to get a good deal that abolishes the anti-democratic backstop. But if we can't get a good deal, we'll have to leave without one.
"This additional £2.1 billion will ensure we are ready to leave on October 31 - deal or no deal."
Mr Johnson has ordered planning for a no-deal Brexit to be ramped up, even though he has claimed the odds of it happening are a "million to one against".
The Prime Minister sent his top Europe adviser David Frost to Brussels to deliver his message that the UK will be leaving on October 31 "whatever the circumstances".
On Tuesday, Brexit minister Stephen Barclay said he has told chief Brexit negotiator Michel Barnier that he wants a deal but will leave the EU on October 31 with or without one.
Shadow chancellor John McDonnell said: "This is an appalling waste of taxpayers' cash, all for the sake of Boris Johnson's drive towards a totally avoidable no-deal. This Government could have ruled out No Deal, and spent these billions on our schools, hospitals, and people.
"Labour is a party for the whole of the UK, so we'll do all we can to block a no-deal, crash-out Brexit - and we'll deliver a transformative economic policy that delivers for the many, not the few."