The British Chancellor of the Exchequer has admitted that a hard border on the island of Ireland is likely in the event of a no-deal Brexit.
Speaking at a fringe event at the Conservative Party conference in Birmingham, Philip Hammond said that World Trade Organisation (WHO) rules would "require checks at the border."
He said: "The challenges around the Irish border are around the legal requirements we will have if we are not in a trade block within the European Union to operate the WTO compliant border, which does require checks at the border.
"That's what the WTO rules require."
"We are depending on the WTO to regulate our relations with the rest of the world, we will have to comply with the rest of WTO regulations or we will find we can't enforce our WTO rights against others".
It is the first time a senior British government minister has admitted a hard border may have to be imposed.
Earlier at the Conservative Party conference, Mr Hammond compared British Prime Minister Theresa May's Brexit plan to the light bulb - and called on colleagues to unite behind her to get the "best possible outcome" in the negotiations.
"A plan which delivers"
In his earlier speech, he said he shared Mrs May's "determination" to get her Chequers blueprint for Britain's EU exit agreed.
The plan has provoked fierce opposition from many within the UK party, who claim it would leave Britain too closely aligned to EU rules and fail to deliver on the result of the 2016 referendum.
While Mr Hammond said he was maintaining "enough fiscal firepower" to support the economy in the event of a "no-deal" Brexit, he predicted a "deal dividend" onceMrs May agrees an exit deal.
He described Chequers as "a plan which delivers on the decision of the British people; avoids a hard border in Ireland; preserves our precious Union and safeguards British jobs and British businesses".
And referring to opposition to elements of the plan from Brussels, Mr Hammond told delegates: "Mr Tusk says it won't work, but that's what people said about the light bulb in 1878.
"Our job is to prove him wrong."
British Prime Minister Theresa May | File photo
Mrs May has consistently said there would be no hard border on the island of Ireland.
Speaking in July, ahead of a visit to the border area, she said: "Daily journeys will continue to be seamless and there will be no checks or infrastructure at the border to get in the way of this.
"I've also been clear we will not accept the imposition of any border down the Irish Sea and we will preserve the integrity of the UK’s internal market and Northern Ireland’s place within it."
