British politics is entering a phase that could be “very dangerous” for Ireland, the Taoiseach has warned.

Leo Varadkar said a Eurosceptic Tory who wants to “repudiate” Britain’s EU Withdrawal Agreement could replace outgoing Prime Minister Theresa May.

After Mrs May announced she will step down as PM and Tory leader on June 7, Mr Varadkar said no matter who replaces her, Ireland will hold its nerve.

Speaking in Dublin after voting in the European and local elections on Friday, he said: “Obviously as anyone can see, British politics is consumed by Brexit and will be consumed by Brexit for a very long time.

“It now means we enter a new phase when it comes to Brexit and a phase that may be a very dangerous one for Ireland.

“In the next couple of months we may see the election of a Eurosceptic prime minister who wants to repudiate the Withdrawal Agreement and go for a no-deal, or we may even see a new British Government that wants a close relationship with the EU and goes for a second referendum.

“Whatever happens we are going to hold our nerve, we are going to continue to build and strengthen and deepen our alliance across the European Union, and we will make sure we see Ireland through this.”

He also paid tribute to Mrs May, saying he will miss her and her team.

“We worked very closely on issues over the past one-and-a-half years on Brexit and the North,” he added.

“I particularly want to pay tribute to her to agreeing to retain and strengthen the Common Travel Area.

“As a result of the agreement we made, British and Irish citizens are able to live, work, study, travel and access health care, housing, education and welfare and pensions in each other’s countries as though we are citizens of both.

“That is going to be there and protected no matter what else may happen as a consequence of Brexit and part of that was done because of her work with us, and I want to pay tribute to her and her team for that.”

He had earlier praised Mrs May, saying: “She is principled, honourable and deeply passionate about doing her best for her country, and her party.”

Irish Foreign Affairs Minister Simon Coveney, meanwhile, repeated previous warnings that the EU will not renegotiate the Brexit withdrawal deal – no matter who the UK’s next prime minister is.

“This idea that a new prime minister will be a tougher negotiator and will put it up to the EU and get a much better deal for Britain? That’s not how the EU works,” Mr Coveney told Newstalk.

Micheal Martin, the leader of Ireland’s main opposition party Fianna Fail, said of Mrs May’s departure: “Her fate is a reflection of the emerging and ongoing crisis in British politics as a result of Brexit and is a reminder of how unstable and potentially damaging this process remains.

“The coming leadership election within the Conservative Party has the potential to further destabilise the Brexit process.

“In Ireland, those of us entrusted with positions of leadership must remain vigilant and stay alert to the threat of a no-deal Brexit.

“Our hope will be that her replacement is someone with the skills and determination to achieve the compromise needed to allow the UK and the EU to move on.

“We must also ensure that this development is not used to further delay the restoration of the Executive and Assembly in Northern Ireland.”

Ireland’s Labour party leader Brendan Howling said Mrs May’s resignation represents the “exhaustion of the current political process around Brexit”.

He added: “In Ireland, we must move our preparations to an ‘orange warning’, as the risk of a disorderly no-deal Brexit is now a real and present danger to jobs and the economy.”