The British government has said the recruitment of extra border officials has been speeded up in preparation for leaving the EU "hopefully by the end of October".
Chief Secretary to the Treasury Rishi Sunak defended increased spending on preparing for a potential no-deal Brexit, saying the government's "clear desire" is for the UK to leave the EU by 31 October.
Speaking on BBC Radio, Mr Sunak said: "A lot of the money we are spending is going to go on things that would need to spend anyway because we are leaving the European Union.
"That means we're going to be leaving the single market and the customs union, so of course that does mean changes to how we trade with Europe."
Mr Sunak said 250 new Border Force officials "will be on the front line" at the end of October, and that a further 250 would join them over the following months.
"We have already been investing in preparing our borders," he said. "We had £2.1 billion allocated for Brexit preparedness in the last financial year, and an additional £2.1 billion this year. This comes on top of that. Part of that has already gone on our borders and HMRC.
"We have already got 500 new Border Force officials working. The 500 extra that we've announced today, recruitment is already in process.
"The procedures have already been centralised, they have been sped up, and 250 of those will be on the front line at the end of October, with a further 250 to come over the coming months."
The UK's economy is strong enough to cope with a no-deal Brexit and while the government wants a better divorce deal it will exit on 31 October without a deal unless the European Union agrees to a better one, finance minister Sajid Javid said.
"Our economy is fundamentally strong, so today we can make many choices," the Chancellor said.
"We can choose to invest in schools, our hospitals, our fantastic police, for example, but we canal so prepare to exit the EU and if that means leaving with no deal that is exactly what we are going to do."
"We have been clear we want to get a deal, but it has to be a different deal, a good deal, one that abolishes this undemocratic backstop, and if we cannot remove that backstop then we have to leave with no deal and we will be ready to do that," Mr Javid said.
Meanwhile, Commons leader Jacob Rees-Mogg said the European Union should realise the new government would not be "browbeaten" by Brussels.
In his Conservative Home podcast he said: "They should believe us because of our new leader. The new Prime Minister is somebody of considerable force of personality who is not going to be browbeaten by them.
"They should believe us because of the appointment of Dominic Cummings, which seems to me to be exceptionally important as a statement as to what is going to happen.
"That ought to make the EU realise that it is not business as usual. It isn't a sort of wet establishment that will go along with Brino (Brexit in name only).
"It is a tough-minded, clear-sighted government that will accept a decent deal, a fair deal, but will not accept a bad deal and isn't frightened of leaving."
Additional Reporting Reuters