It could take a further two years for Britain to fully leave the EU and start negotiating new trade deals with other countries, Liam Fox has said.
The international trade secretary told the BBC there could be a two-year “implementation phase” after the UK officially left the EU, in March 2019.
He had “no ideological barrier” to a phase to help business adjust, he said.
Mr Fox denied he was planning for a situation in which the UK left the EU without a deal.
It follows reports of cabinet divisions over Brexit, with Chancellor Philip Hammond saying last month that no deal with the EU “would be a very, very bad outcome”.
If the UK leaves the EU without a trade agreement it could default to World Trade Organisation rules, potentially facing tariffs on goods and services traded with the EU.
Mr Fox said the UK could “of course survive with no deal” but he wanted a “full and comprehensive deal” with the EU.
He also said “the free trade agreement that we will have to come to with the European Union should be one of the easiest in human history” because the UK already met EU standards.
Some MPs have called for the UK to remain in the EU’s single market and customs union after Brexit. Some non-EU European countries, such as Norway, are members of the single market.
Mr Fox said that he did not “have a problem” with a transitional Brexit deal, which he described as an “implementation phase” but insisted: “You can not leave the European Union and be in the single market and the customs union.”
‘No ideological barrier’
Speaking after a speech in Geneva, where he is meeting the WTO’s director general, Mr Fox implied that such a phase could last two years.
Earlier this month, Mr Fox told Bloomberg TV he would be “very happy” with a transitional phase lasting “a few months”.
He told the BBC: “We’re going to leave [the EU] in March 2019.
“But if we can do it in a way that minimises or avoids any disruption to business, that provides them with the greatest amount of certainty and stability, then that’s clearly a sensible thing to do.
“And if we have an implementation phase between us leaving the European Union and moving to whatever new arrangement and relationship we have with the EU, I don’t have any problem with that, for me there’s no ideological barrier to that.”
Mr Fox said he had been waiting to leave the EU “for a very long time, another two years, say, wouldn’t be too much to ask”.
And he said the UK would want to be able to “negotiate and conclude” trade deals outside the EU after March 2019 – but that was something that would be subject to negotiation.
BBC political editor Laura Kuenssberg said Mr Fox’s apparent acceptance of “some kind of transition” indicated “a change in tone from Brexiteers” since the general election.
Lib Dem Brexit spokesman Tom Brake said: “I think the penny has finally dropped even with Liam Fox, that what the Brexiteers had presented as a simple, straightforward process that could be completed within a couple of years, now they realise that there’s probably going to be a couple of years on top of that, and even that may be an underestimate.”
Mr Fox’s Labour shadow, Barry Gardiner, said any trade deal with the EU would have a political dimension.
Mr Gardiner said: “Liam Fox seems to be saying it makes economic sense for the EU to give us a good deal and we already have the basis for that, so why don’t they just say, ‘Right, we’ll keep it as it is.’?
“But of course that ignores the fact that the European Union too has its own political objectives, and they are about ever-closer union of the remaining 27 and ensuring that nobody of those 27 feels that they too might get a better deal outside of Europe than inside.”
Mr Fox also said earlier that the UK would take up an independent seat on the World Trade Organisation after Brexit and he believed that talks with the WTO indicated that “we will simply replicate our current obligations under the European Union as we move into the United Kingdom as an independent member”.