But there is a youthful bounce to this former communist, aged 66, who behaves more like a student activist than a retired school teacher. Whether organising a demonstration or speaking out to visiting journalists against the regime of President Mubarak, the co-founder of the Kefaya (Enough) movement feels that his time has finally come.

“I have been waiting a quarter of a century for this moment,” said Mr Ishaq, whose flat in Cairo has become a centre, if a chaotic one, for a broad spectrum of opposition figures, who troop in and out, organising protests and picking up leaflets.

“We have finally broken the culture of fear in this country. People thought Mubarak was a half-president, half-god, that he was a Pharaoh, that he was untouchable. Now we have the right to challenge him and say 24 years of Mubarak and his regime is enough,” he said, punching the air with satisfaction.

Government ministers are probably right to dismiss the small and disparate opposition challenge, and say that Mr Mubarak will be easily re-elected to a fifth presidential term in September; yet everyone agrees that something has changed in the Arab world’s largest and most influential nation.

Half a dozen independent newspapers feel free to criticise Mr Mubarak, his Government and even his family, when once that could have meant prison. Where the ruling National Democratic Party had a monopoly on power for three decades, now dozens of parties and political movements are springing to life. Where it was assumed that Mr Mubarak, 77, would rule for ever, now the main debate in Egypt is who will succeed him.

Egypt’s version of the “Arab Spring”, as the democratic changes sweeping the region are known, is particularly significant because it has the strong encouragement of Washington. President Bush has stated repeatedly that he wants Cairo to set the example for democracy and is putting pressure on his key Arab ally to introduce the necessary reforms.

Mr Mubarak does not have much choice. America provides nearly $2 billion annually in aid to Egypt. Its embassy in Cairo, the largest American mission in the world, is openly supporting pro-democratic forces. When Condoleezza Rice, the Secretary of State, arrives in Cairo this month, democracy will be at the top of her agenda. Not long ago Cairo would look forward to such a visit; now there is unease. “I am sure they are dreading Condoleezza Rice coming out,” a Western diplomat said.

The apprehension is well founded. This month Mr Bush telephoned Mr Mubarak to berate him over the attack by activists of his ruling party on an opposition demonstration where women protesters were sexually assaulted. The Americans are pressing Cairo to accept international observers to monitor the elections. They intervened to help to secure the release from jail of Ayman Nour, a liberal politician who shot to fame after announcing that he would challenge Mr Mubarak in Egypt’s first multi-candidate elections in September.

At his penthouse flat in Cairo’s fashionable Zamalek district, the softly spoken 40-year-old leader of the al-Ghad (Tomorrow) party cuts an unlikely alternative to Mr Mubarak, who is a former Air Force officer and one of the world’s longest-serving heads of state. Mr Nour’s critics dismiss him as an opportunist with no hope of winning. But he has probably correctly judged that he is destined to play an historic role, if only in changing the way Egypt chooses its future leaders.

“I can’t convey to you how fed up the ordinary Egyptian is that we have had one ruler for our nation for 24 years,” he said. “It is an ugly thought that Mubarak thinks he can rule for another six years and then bequeath the leadership to his son. Someone has to stand against him.”

Talk of a father-to-son succession infuriates the President’s Western-educated son Gamal, 42. This former banker, with clear political ambitions, is the driving force behind efforts to reform the Egyptian economy and modernise the ruling party. But he insists that he has no intention of becoming the next Egyptian leader. “This fallacy should be put to rest,” he said. “I have no ambition to become the next President.”

Any hopes of easing the son into the father’s job, as Arab leaders have done in Syria and Jordan, has been greatly complicated by President Mubarak’s announcement in February that he would allow candidates to challenge him for the presidency. No one doubts that he will win the next presidential elections, where he can count on the support of a huge party machine, millions of public sector employees and government workers and, crucially, the backing of the Armed Forces.

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