The Brexit secretary told the Cabinet on Tuesday there has been a “significant acceleration” in the preparations for Brexit, which already cost half a billion pounds, and the need for a total of 8,000 extra staff.
HMRC has already hired 3,000 extra staff, 300 of them Brexit lawyers.
HMRC’s chief executive Jon Thompson said last week the Revenue had already received £78m of the £250m set aside by the government to help departments prepare for a "no deal".
Speaking to the cross-party Public Accounts Committee, Thompson said the Revenue would need “several hundred million pounds” if the UK left the European Union without a trade deal in 2019.
“In that scenario, you are looking at an estimate of between £300m-£450m.”
Thomson said at the time that the number of people working in the National Clearance Hub would need to be “ramped up” to cope with the changes. But he could not guarantee the new Customs Declaration System (CDS) would be ready for 2019 as there were significant risks to the programme.
Davis said during the Cabinet meeting that the government’s proposed customs arrangements will require investment in new systems and customs officers, regardless of the outcome of the Brexit negotiations.