Irish Foreign Minister Simon Coveney says the EU is in "no mood" to change the Withdrawal Agreement significantly after Theresa May's defeat in Westminster on Tuesday.
Coveney, who is also Ireland's deputy leader, added that he believes the Prime Minister will survive the vote of no confidence tabled by opposition leader Jeremy Corbyn.
On RTE's Morning Ireland programme on Wednesday, Coveney said: "There is so much still to happen in Westminster in the next few days before it becomes clear what Britain is asking for.
"It's hard for us as EU leaders to respond in a helpful way if we still don't know what they are asking for.
"We need to hold our nerve this week. There's a motion of no confidence today, I believe that will be lost, and my understanding is that the Prime Minister's intention then is to try and reach across parties to try and find a way of getting a majority in Westminster to support a new approach.
"When we understand what that new approach is, which we get next Monday, we'll try and respond in a helpful way."
Coveney noted that the Withdrawal Agreement was signed by 28 governments including Britain.
"I don't think the EU is in any mood to change the Withdrawal Agreement significantly at all," he added.
"We don't even know what the ask is, we'll have to wait and see what they're asking for.
"Those who have rejected the backstop do not have alternative solutions in terms of how we provide reassurance (on the border)."
He added: "If there isn't a future relationship that resolves the border issue, then the backstop will kick in which involves minimal checks on goods moving from Great Britain into Northern Ireland.
"The position is we support the backstop. The Irish Government have made very clear that we are not going to start talking about alternatives to the backstop. It took us two years to negotiate an approach that can provide the guarantees that we have given to people.
"We're not going to allow physical border infrastructure to reappear."
Coveney concluded saying Ireland will not block any UK request to extend Article 50 but there needs to be a plan.
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