Some elements of the British establishment "can't believe we won't fall into line" on Brexit, Taoiseach Leo Varadkar has said.
While accepting that Anglo-Irish relations are "strained", Mr Varadkar risked heightening tensions further with his comments in front of more than 1,000 business leaders.
"You do come across people in the British establishment who can't believe we won't fall into line. They thought 'sure you'll be leaving too, won't you?'. The fact that we aren't and that we have stood up for ourselves has made some of them quite annoyed - but so be it," the Taoiseach said.
"You'd swear we created the problem. Obviously we didn't, it's one of other people's making."
Mr Varadkar's comments will be closely observed by members of Prime Minister Theresa May's Conservative Party who have varied views on how she should deal with the Border question.
The Taoiseach said "individual personal relationship, minister to minister, prime minister to Taoiseach, are actually very good because we have to talk so frequently now", but in a "wider sense" are "strained".
"Brexit has created a disturbance in the force. And they are strained as well because of Northern Ireland. The institutions there are not up and running and the UK government is dependant on one party.
"Our policy is to try maintain relationships - political, trade, economic - as they are as much as possible.
"My objective is to give businesses certainty as soon as we can. We had hoped to have a deal done by now.
"It's not part of our strategy to drag it out to the last minute."
The Taoiseach said a lot of people in the UK had great respect for Ireland and "understand our concerns", but others didn't think about the impact of Brexit on this island.
Tánaiste Simon Coveney said there was a "misunderstanding" among some in London on how the so-called 'backstop' for Northern Ireland was arrived at.
He noted it was agreed to by Mrs May last December and again in March as part of an "under-rated agreement".
He said the "insurance mechanism" must be agreed to first before the withdrawal deal is confirmed and it must remain in place "unless and until something better is agreed".
"We're starting by reassuring everybody that there is a floor here below which we can't fall.
"There is not going to be the emergence of a hard Border. Now let's negotiate something better to make that backstop unnecessary," Mr Coveney said.