There’s a thin line between well-organized and over-organized. On the one hand, the fact that the Muslim Brotherhood will be joining tomorrow’s regime-crushing demonstrations in Egypt looks likely to bring mass mobilization to a level that even an authoritarian government lacks the power to stop. At the same time, the fact that the Islamist movement has waited this long to join the action calls into question its capacity to lead the revolution and dominate a new government.

The Financial Times reports:

After decades of political apathy in this society of 80m people where few bothered to vote and protests usually drew tiny numbers, the explosion of anger has also taken the country’s opposition politicians by surprise.

Although the demonstrations are essentially leaderless, organised by youth activists on the internet, the opposition is now scrambling to use the opportunity to press for an end to the Mubarak era.

Politicians in Cairo say the National Association for Change headed by Mohamed ElBaradei, the Nobel laureate and former chief of the International Atomic Energy Agency who was due to land in Cairo last night, will emerge from the Egyptian “intifada”, or uprising, with enhanced credibility. But whether the regime will allow Mr ElBaradei to assume a leadership role remains to be seen.

The national association comprises several leading political figures and intellectuals, youth groups like April 6 which has been instrumental in mobilising demonstrations through the internet and a few political parties, including representatives from the Muslim Brotherhood.

The Islamist group is considered the movement with the largest grassroots support in the country but has always been reluctant to provoke the regime. It gave only timid support to the youth activists’ call for a “day of wrath” on Tuesday, though it is calling for participation in the rallies that are planned on Friday.

Opposition leaders say Mr ElBaradei, in particular, has played a crucial role in encouraging young Egyptians in their activism. He returned to Egypt a year ago, after living abroad for three decades, amid activists’ calls on him to run against Mr Mubarak in the September presidential elections.

His response was that he would heed the calls if the constitution was changed to allow independent candidates. Recent amendments to the constitution, as it stands today, give the ruling National Democratic party of Mr Mubarak control over the presidential election process.

Mr ElBaradei’s contribution, say opposition leaders, was to articulate the calls for reform and demonstrate that there are alternatives to Mr Mubarak. “No one can claim this wave . . . but what ElBaradei said and did helped light the flame,” said Osama el-Ghazali Harb of the Democratic Front party, which is part of Mr ElBaradei’s National Association. “He put forward the demands of the opposition and he gave them international attention.”

Issam el-Erian, a brotherhood leader, concurs. “El Baradei had a big role in starting this wave,” he says. “The system was always saying there is no alternative and the only one is the Ikhwan (Brotherhood), but he offered an alternative, and he has a Nobel prize, so he’s a respectable alternative.”