Taoiseach Leo Varadkar has warned Boris Johnson that Britain will get no future trade deal with the EU if there is no backstop after Brexit.

Mr Varadkar also said he was not sure whether the new British prime minister was "bluffing" with his threats to crash Britain out of the EU without a deal.

Speaking at special Cabinet meeting in south Donegal, he said:

“It is going to be a matter for the United Kingdom to decide whether or not it is a member of the European Union in 2026. They had the referendum and we respect the result.

“No deal is a British threat. The only people who can cause a no deal is the United Kingdom government.

While I'm not going to speak to Prime Minister Johnson over the airwaves, I look forward to meeting him in early course. What I can say is the position of the European Union and the position of Ireland has not changed.

"The backstop is an integral part of the Withdrawal Agreement. Without the backstop, there is no Withdrawal Agreement, there is no transition phase, there is no implementation phase and there will be no future trade agreement until all those matters are resolved.

“So I hope the prime minister hasn't chosen a no-deal, but that will be up to them."

Asked by reporters if Mr Johnson was "bluffing" with his threat to take Britain out of the EU without a deal, he also responded:

“I don't know.”

Earlier today, Mr Johnson insisted that the backstop must be abolished to move Brexit forward.

"It must be clearly understood that the way to the deal goes by way of the abolition of the backstop," Mr Johnson said in his first speech in the House of Commons as prime minister.

He said the current terms of the Withdrawal Agreement were unacceptable "to this parliament and country".