THE British public should be "comforted and reassured" that the UK Government is preparing the country for a no-deal Brexit with plans for the stockpiling of food and medicines, Theresa May has said.

The Prime Minister’s remarks came after Simon Coveney, the Irish deputy premier, dismissed talk of a no-deal as “bravado” and warned Britain that it “could not afford” to crash out of the European Union without an agreement.

In an interview with 5 News, Mrs May did not deny stockpiling was happening and insisted the Government was being "responsible and sensible" while still trying to get a good deal with Brussels.

Her comments came as Philip Hammond, the Chancellor, on a visit to Belfast, also insisted no-deal contingency planning was a “sensible and responsible thing for a government to do and large businesses that are importing or exporting large volumes of products or produce will be making contingency plans”.

He added: “And we would encourage them to do so and work closely with them as they are putting those plans together."

Earlier this week, Matt Hancock, the UK Health Secretary, told MPs he had asked officials to "work up options for stockpiling" by the pharmaceutical industry while his Cabinet colleague Dominic Raab, the Brexit Secretary, said the Government would also take steps to ensure an "adequate food supply".

The PM said: "Far from being worried about preparations that we are making, I would say that people should take reassurance and comfort from the fact that the Government is saying we are in a negotiation, we are working for a good deal - I believe we can get a good deal - but...because we don't know what the outcome is going to be... let's prepare for every eventuality.

"This is not just about stockpiling. That concept, what it is, is about making sure that we will be able to continue to do the things that are necessary once we have left the European Union, if we leave without a deal."

Her comments came as a new poll suggested trust in her ability to handle Brexit was falling quickly.

An ICM poll for The Guardian found she had an eight-point lead over Labour leader Jeremy Corbyn over who could be trusted to negotiate a good Brexit deal; down from 16 points in January and 34 points before the 2017 General Election.

On the parties’ standing, it put Labour on 41 per cent, up two points from a fortnight ago, Tories down one point on 40 per cent, with Lib Dems on eight points, Ukip on five and the Greens on three.

Earlier, Mr Coveney made clear Dublin would back any request from the UK for an extension to the Article 50 process to give more time to negotiate its withdrawal from the EU.

While he said there was still time to reach agreement by October, he called for an "intensification" of the talks at official level over the summer to resolve outstanding differences.

The Irish minister warned that certain elements of the UK negotiating position as set out in the UK Government’s Brexit White Paper would be difficult for Brussels to agree to although he noted that the document had made negotiations "easier" by backing away from earlier red lines.

Mr Coveney dismissed suggestions that amendments to the Brexit legislation had forced on the PM by Eurosceptic backbenchers would prevent agreement on a "backstop" arrangement for the Northern Irish border.

His remarks came ahead of a meeting on Thursday between Dominic Raab, the Brexit Secretary, and Michel Barnier, the EU’s chief negotiator, and Mrs May’s trip to Salzburg on Friday for talks with her Austrian counterpart.

On Tuesday, the PM confirmed that as the Brexit talks entered their final weeks she was taking personal charge of them with Mr Raab "deputising" for her in Brussels.

Tory Eurosceptics voiced concerns that the Brexit Department had been “sidelined” by No 10 and Mrs May's Europe chief adviser Olly Robbins, amid increasing speculation that divisions within the Conservative camp could result in a no-deal Brexit.

In a separate development, Lord Trimble, the former First Minister of Northern Ireland, warned that any attempt by the Irish Government to impose post-Brexit tariffs on trade with the UK would lead to an upsurge in smuggling at the Irish border.

The Conservative peer said an increase in smuggling would have the "delightful" side-effect of diverting criminal elements away from paramilitary activity by giving them something more useful to do.

But he said the better solution would be the removal or reduction of tariffs across the whole British Isles.

The former leader of the Ulster Unionist Party called on Dublin to press Brussels for a British Isles exemption from the requirement to collect tariffs on trade with countries outside the EU.

"It's in its own interests for them to speak to the EU about tariffs and about the reduction or elimination of tariffs within the British Isles.

"That would be a huge step forward for everyone and it would solve all the other problems, including the problems that have been manufactured by people over the course of the last year or so," added Lord Trimble.