Once again, mobile-phone operators have come under fire for the charges users are subject to when texting and surfing the web abroad.

Texting from overseas currently costs up to 49p, while users transferring 1MB of data are on average charged £4.11. According to EU Commissioner Viviane Reding, operators will once again face regulation unless prices are lowered. Last year saw the EU force companies to lower the costs of making calls abroad.

Reding will warn mobile-phone operators during her speech at the GSM Mobile World Conference in Barcelona this week. She told the BBC that the deadline for operators to lower charges is July 1.

"If the industry does what it claims it can do, bringing prices down to normal, then of course, regulation will not be necessary," she said.

The warning won't come as a shock to mobile phone operators. At the end of January, regulator Ofcom highlighted that another pricing clampdown by the EU was likely unless texting and surfing charges abroad were lowered.

In a statement, Ofcom chief executive Ed Richards said: "We want to see industry take the initiative on this issue or we may need to see further action at the European level since national regulators are unable to address these issues unilaterally."

Last week, Vodafone announced it was voluntarily reducing its monthly data roaming tariff for European business travellers and increasing the amount of data a customer can use from 100MB to at least 150MB. The company described the reduction as "a move designed to make it even more affordable for customers to use their laptop computers wirelessly when abroad". Whether it's enough to stop the EU enforcing another pricing regulation will remain to be seen.