Egypt's telecommunications regulator has imposed new restrictions on mobile text messages ahead of legislative elections.

Mahmoud el-Gweini, adviser to Egypt's telecommunications minister, said on Tuesday that companies sending out text messages en masse - known as SMS aggregators - must now obtain licenses.

Opposition activists say the new regulation stifles their ability to mobilise voters.

Reform groups in Egypt have come to rely increasingly on the internet and mobile phones to organise and mobilise their supporters, tools which have enabled them to sidestep government harassment.

The Muslim Brotherhood, a well-established but technically outlawed Islamist party, used text messages as a campaign tool for its candidates in the elections five years ago. The party surprised the government in 2005 by winning 20 per cent of parliament seats. 
 
El-Gweini said the decision was not supposed to curb political activity, but rather to protect people from "random" text messages about sensitive issues.