Holidaymakers are to be warned about the impact of a potential no-Brexit deal.

British travellers could be warned about the potential for huge disruption at ports and airports and be advised to buy additional insurance if reciprocal health arrangements are invalid.

Reports today suggest UK prime minister Theresa May will put the country on a “no-deal footing” this summer as negotiations on the terms of Britain’s leaving the EU continue to progress slowly.

The Times said consumers and companies will be given weekly ‘bundles’ from next week including advice on how to prepare for a “disorderly Brexit”.

A leading civil servant, John Mazoni told MPs yesterday Britain was doing what it could to prepare for a no-deal outcome but that it was difficult to predict how EU states would react.

The government has said that it is doing all it can to avoid a no-deal outcome but that it’s priority was to make sure citizens, businesses and organisations are kept informed and reassured.

The government has set aside £3 billion for no-deal contingencies but only half of that has been allocated, according to The Times.

Meanwhile, the Irish prime minister Leo Varadkar has warned international flights from the UK would not be able to operate in the event of a no-deal Brexit.

He said: “The situation at the moment is that the United Kingdom is part of the single European sky, and if they leave the EU they are not and that does mean that if there was a no deal hard Brexit next March the planes would not fly and Britain would be an island in many ways and that is something that they need to think about.

“If they want their planes to fly over our skies, they would need to take that into account,” the Taoiseach said during a press briefing after the Irish Cabinet met for discussions at an away-day in Co. Kerry.

“You can’t have your cake and eat it. You can’t take back your waters and then expect to take back other people’s sky.”

May told a committee of MPs this week that the UK wants to participate in the European Aviation Safety Agency (Easa) after Brexit as a non-EU member state.

“We believe that what is in this White Paper is the right package to put forward,” but she added that the Department for Transport was “looking at what would happen in a no deal scenario and what arrangements would need to be in place.”

“It is in everybody’s interests to ensure that the planes can still fly,” she added.