The referendum is over. So what's next, asks Amira Howeidy "Sometimes we differ, sometimes we get upset with each other, but we always end up together." So ran the lyrics of one of the many singing TV ads aired by the state in an attempt to encourage people to vote in yesterday's referendum. The invitation to irony was hard to overlook. Togetherness, unity -- the ads hammered home their message against a backdrop of what the pundits conveniently call a state of polarisation. On one side of the divide is the state, on the other the opposition. And if there is any unity in evidence it is to be found in the ranks of the opposition who have called an unprecedented truce in order to boycott the referendum. As young singers harped on about patriotism and freedom in the seemingly endless broadcast of video clips the security forces were busy clamping down on the Muslim Brotherhood, arresting 15 members on the eve of the referendum to bring the total number of the detained Muslim Brothers to more than 900. And for good measure, they then turned their attention to the previously unknown Youth for Change, arresting four left- wing activists in Maadi for promoting a boycott of the referendum. The arrests catapulted the hitherto obscure Youth for Change group into the limelight which they now share with the Egyptian Movement for Change (Kifaya), the Tagammu, Wafd, Nasserist and Al-Ghad parties, and the Muslim Brotherhood, all of whom united to boycott the referendum. The ranks of the anti-government front were further swelled by members of the Judges' Club, who have threatened to withdraw their supervision of elections until judicial independence is guaranteed, and by university teachers, who are demanding, among other things, an end to the heavy-handed tactics of security forces on campuses. The intensity of the state-run campaign to mobilise ordinary Egyptians into voting -- until now they have been systematically ignored -- may reflect official concern at the coalescing of an anti- government coalition, though it could equally be an attempt to convince the US, which is taking a great deal of interest in Egypt's elections, that the regime is serious about democratisation. But now the referendum is over, what next? Most commentators anticipate President Hosni Mubarak will finally announce his intention to run for a sixth presidential term and no one is betting on a defeat. But given the volatility of the current situation the four month run up to September's presidential election remains unpredictable. Tagammu Party leader Khaled Mohieddin and Al-Ghad Party President Ayman Nour are expected to make the headlines as they implement their decisions to contest presidential elections. While many think 82 year old Mohieddin will withdraw from the contest in its early stages Nour, 40, remains adamant that he will see the campaign through to the end. In an interview with Al-Ahram Weekly Nour refused to accept the prevailing view that the results of the elections are a foregone conclusion, with Mubarak guaranteed an easy victory. "The presidential election remains open," he said, "unless it is conducted along the same lines as the referendum." And if that happens? "In that case," says Nour, "I might change my mind about running." And if the judges refuse to supervise the vote? "Then I certainly won't run. But at this stage," he added, "nothing is clear and anything can happen." Unity among opposition ranks is likely to be one of the first casualties of the presidential election as the Tagammu and Al-Ghad enter the contest and many wonder whether it is worth undermining the existing opposition front. "We only agreed to boycott the referendum," says Nour. "There was no agreement regarding presidential elections." The Muslim Brotherhood has already made up its mind to boycott the September poll. "We will boycott presidential elections just as we boycotted the referendum," says Abdel-Moneim Abul-Fotouh, a member of the Muslim Brotherhood's guidance council. "We won't support Mubarak and we won't support Nour." While the judges, Kifaya and the Brotherhood are expected to be the main sources of pressure on the government in coming months no one is predicting where such pressure might lead. While insisting the Muslim Brotherhood would continue to "press for reform by peaceful means", Abul-Fotouh refused to say whether or not the group will change its tactics should the government continue to arrest its members. And there are other factors at play. Wael Khalil, of the Popular Campaign for Change, points to recent statements by US State Department spokesman Richard Boucher, and to this week's visit to Egypt by Laura Bush. That Boucher was careful not to condemn the Brotherhood arrests, and argued there are as yet no facts to warrant criticism of Egypt's electoral process could, says Khalil, signal Washington's approval of the way the regime is conducting itself. It is an impression reinforced, he argues, by Laura Bush's remarks on President Mubarak's "wise" moves towards reform. "These signals could give a green light to the government to continue with its arrests," claimed Khalil. Tareq El-Bishri, an ex-judge and leading proponent of reform, is equally sceptical over the real intentions of the government. They endlessly promise that domestic reforms will follow the referendum, he says, but give no details. "If reforms are in the pipeline why does nobody say what they are?" "We want to believe the state is serious about reform," says Abul-Fotouh. "But how can there be reforms when arrests are the order of the day?"