Consumers across Europe should be able to pay the same for using their mobile phones abroad as they do in their home country for an unlimited number of days, under plans being debated by the European commission as it tries to abolish roaming charges.

The commission discussed new proposals on Wednesday as part of an EU plan to abolish roaming charges by June 2017, after Brussels officials were forced into a U-turn.

Roaming charges have become a political football, as the EU executive searches for ways to give the European project more popular appeal amid the eurozone debt crisis and Brexit negotiations.

The cost of sending messages and making calls abroad has been slashed by more than 90% since the EU began capping roaming charges in 2007. Now the commission wants to phase out roaming charges entirely by next year.

But Jean-Claude Juncker, the European commission president, ordered his officials to rewrite the draft plans after deeming they did not go far enough.

Under a previous draft, telecoms companies would have been allowed to charge people more for using their phones abroad for more than 90 days a year. But Juncker ordered his officials to go back to the drawing board, after criticism from members of the European parliament.

The change has alarmed the telecoms industry, which argued that 90 days was already stretching the definition of periodic travelling. The average EU citizen is abroad for 12 days a year and only 0.1% of European consumers will be affected by abolishing the 90-day cap.

Andrus Ansip, a European commission vice-president, said the earlier plan had not won support. “It wasn’t accepted by member states or service providers. It was one idea, [but] it didn’t fly.”

Mobile phone costs vary significantly across the 28-country bloc, with prices in Latvia more than six times cheaper than in Ireland. Phone companies are concerned the law would mean consumers could buy cheap sim cards in one country and use them permanently in another. They claim cheaper companies would be saddled with the higher costs of customers who are not genuinely roaming.

In response, the commission has promised to introduce safeguards: telecoms companies would be able to check on consumers who appear to be permanently roaming and charge them more. Customers will be able to complain to national telecoms regulators if they dispute the charges.

Consumer groups argue that phone users face unjustified costs. One survey cited by the European Consumer Organisation (BEUC) found that roaming calls could cost up to €2 (£1.70) a minute – 20 times more than the cost of making a domestic call.

Monique Goyens, the BEUC director general, welcomed the decision to drop time limits on roaming. “Consumers should be able to make phone calls, send messages and use the internet for the entirety of their stay abroad and not be charged additional costs when travelling for a long period of time, working or studying in another EU country.”

But questions remain about how abuse of the proposed regime will be defined and policed. Phone operators will be responsible for checking suspected abuse, but industry sources say this raises many practical difficulties, such as checking residence when a British student is doing a six-month course in Germany. “The burden is on the operator to check … and I don’t know what we will do,” one industry source said. “Will we have to ask for the certificate from the university?”

The European Telecommunications Network Operators’ Association, which represents providers including T-Mobile and Orange, said: “A careful evaluation of all the technical, legal and economic aspects of this decision is vital.”

The commission will announce detailed proposals in mid-December, after consultation with telecoms regulators and EU member states.

Roaming charges also feature among the many unanswered questions about Britain’s vote to leave the EU. If the UK were to remain a member of the European Economic Area, which includes all EU member states plus Norway, Liechtenstein and Iceland, British consumers would continue to benefit from the abolition of roaming charges.

But a more detached relationship with the EU could lead to Britons paying higher prices to use their phones on the continent. Swiss consumers pay more for data roaming than any other member state, according to the Body of European Regulators for Electronic Communications. Swiss phone users pay 35 eurocents per megabyte of data when using their phones abroad, compared with an average of 6-7 eurocents across the European Economic Area.

The Bruegel thinktank, which drew attention to the issue in a recent article, concluded that British consumers would pay more to roam after Brexit. It remained “a safe bet” that UK residents with UK mobile subscriptions would pay more for using their phone in Europe than EEA citizens would pay, it said.