Here is a guide on how much texts, calls and internet browsing will now cost in the EU and how to avoid those high phone bills.
The European Union has capped the cost of making phone calls, texting or browsing the internet while abroad.
It should be no surprise that David Cameron failed to stop such a long-standing EU figure being nominated as European Commission president.
A proposed deal that could threaten increased privatisation of schools and the NHS will blow apart the power of democratic decision-making, the leader of the Green Party has said, as protests are expected to erupt over the EU-US trade deal.
Natalie Bennett said: "The Transatlantic Trade and Investment Partnership (TTIP) is a huge threat to hard-fought-for standards for the quality and safety of our food, the sources of our energy, workers' rights, and our privacy".
Protests will be held across the country today against a 'secret' trade deal between the EU and the US that could threaten jobs and public services.
Hundreds of people are expected to march in London, Edinburgh, Brighton, Manchester, Cardiff, Nottingham and other areas.
Those opposed to it say the proposed deal, known as the Transatlantic Trade and Investment Partnership (TTIP), threatens increased privatisation of schools and the NHS, would cut food and environmental rules, and cost jobs.
Nick Dearden, director of the World Development Movement, said: "The deal would hand multinational companies unprecedented powers over life in this country."
Jean-Claude Juncker has insisted he will not try and block British efforts to regain powers from Brussels despite David Cameron's failed bid to prevent him becoming European Commission president.
Mr Juncker said any proposals from Westminster would be "taken under consideration" and stressed that he wants the UK to stay in the EU, the Daily Telegraph reports, citing a leaked recording.
He reportedly told MEPs at a Brussels meeting: "I would like Britain to stay as an active constructive member of the European Union. If Britain puts forward a proposal it will be taken under consideration.
"I don't want the EU without Britain. Britain is an essential element of policy making in Europe because the British are a common sense and down to earth people."
An ITV News/ComRes poll has found that the proportion of Britons that would vote for the UK to stay in the EU has fallen by four percentage points.
The figure has dropped to 36 per cent following the row over Jean-Claude Juncker’s appointment as President of the European Council last week.
If a referendum was to be held, 43 per cent of people would vote for Britain to leave the EU.
And 34 per cent believe membership of the EU is a “good” thing for the country, a fall of three per cent, while 44 per cent say it is a “bad” thing.
David Cameron is set to be grilled by MPs in the Commons later over his failed bid to stop Jean-Claude Juncker being chosen as the next president of the European Commission.
The Prime Minister has faced criticism of his negotiating tactics after he proved unable to block Mr Juncker's nomination to the crucial post on Friday.
Tories have insisted he is set to receive "amazing support" from his backbenchers over the position he took.
However, he is likely to get a rougher ride in the Commons from Labour, whose shadow chancellor Ed Balls has branded the failed negotiations a "catastrophe" for Britain.
Writing in The Daily Telegraph today, Cameron has insisted he can still secure reforms to Britain's relationship with Europe, saying: "I am ready to move on and keep fighting for Britain's interests in Europe."
David Cameron has admitted that his opposition to Jean-Claude Juncker becoming President of the European Commission has made renegotiating the UK's position in Europe more difficult.
"I do not deny that it has made the task harder and the stakes higher," the Prime Minister writes in today's Daily Telegraph.
However he insisted the Government would not be deterred from trying to reform the EU.
"When we encounter setbacks, we don’t throw in the towel: we redouble our resolve. The task of reforming Europe and securing Britain’s place in a reformed Europe was always going to be a long and tough campaign," Mr Cameron argues.
"You don’t turn around a tanker like the EU with ease; this will be tough, and we’ve always known that," he added.
David Cameron has insisted he can "do business" with the new President of the European Commission, despite having vigorously opposed his appointment.
Writing in the Daily Telegraph, the Prime Minister admitted he was "isolated" over the decision to instal Jean-Claude Juncker at the head of the EU's executive branch, but insisted he was "right" to take a strong stance on the issue.
At the same time, Mr Cameron stressed he was now "ready to move on and keep fighting for Britain’s interests in Europe".
He remained clear that his government was strongly opposed to being involved in further EU integration, saying: "If...we can agree that we are not heading, at different speeds, to the same place – as some have assumed up to now – then there is business we can do".
Despite campaigning against him, David Cameron called Jean-Claude Juncker today to congratulate him on securing the nomination to be the next president of the European Commission, Downing Street said.
A spokesman for Number 10 said: "The Prime Minister called the Commission President-designate, Jean-Claude Juncker, this afternoon. The Prime Minister congratulated Mr Juncker on running a successful campaign and securing the Council nomination."
They added: "They discussed how they would work together to make the EU more competitive and more flexible. The PM welcomed Mr Juncker's commitment of finding a fair deal for Britain and Mr Juncker said that he was fully committed to finding solutions for the political concerns of the UK."
Juncker, the former Luxembourg premier told the Prime Minister he was "fully committed" to finding a solution to British concerns about the European Union and they discussed "how they would work together" to boost competitiveness, they said.