Brussels is expected to battle the high cost of data roaming charges this week, as the deadline for operators to take action expires.

The European market for mobile data services is now worth €7bn (£5.5bn), according to industry body the GSM Association. In February Commissioner Viviane Reding set a deadline of July 1 for operators to lower charges for roaming data use, threatening to intervene with regulation if her demands were not met.

Last year Reding oversaw the introduction of the continent's Eurotariff, which sets a price cap on the cost of making mobile voice calls when outside of your home nation. Similar limits could now be placed on the use of other services, said Dr Windsor Holden, principle analyst at Juniper Research.

"It is distinctly possible that we will see that option explored," he said. "Clearly that would not find any favour with the operators, but it is certainly a choice supported by a number of people within the Commission."

But while service providers will have no choice but to obey any regulatory changes, companies may simply transfer their charges to another part of the business, said Holden.

"There are a number of tactics they could employ, from pushing up pre-pay tariffs to increasing the cost of handsets, and none of them will make the overall experience any less expensive to the user."