(ANSAmed) - TUNIS, APRIL 30 - The eve of May the first is marked by a degree of apprehension in Tunis this year. Two marches have been scheduled to take place in the city centre tomorrow - both by trades union organisations. The first of these has been called by the UGTT, the country's general labour union, to take place in Bourghiba Avenue; the second has been organised to take place just a few hundred metres away in Avenue Mohamed V by the Union of Tunisian Workers (UTT). The country's Interior Ministry has impressed upon both union organisations the need to stick to their schedules as well as to the agreed routes. But cause for concern centres rather on memories of what has happened over the past weeks during other marches organised in protest at the policies of the Ennahda-led government. On such occasions, the leafy backdrop of Bourghiba Avenue and other central city streets became the scene of violence enacted upon those taking part in the protests. These incidents led the Interior Minister to impose a ban on any protest marches of any kind in these symbolic venues, but the Ministry has since backed down under pressure from organisations and political parties who pointed out that such a ban comes close to political repression. So tomorrow's marches are to go ahead, and the city will be holding its breath - at least until the early afternoon when they will probably have come to an end. The fear is of a repetition of scenes in which infiltrators whose normal attire helped them to blend in with the other protesters, used the march as a chance to attack the very people who had come out on the streets in order to uphold civil rights. Among their victims were members of professional associations such as the Bar or even elected elected delegates at the Constituent Assembly attacked while carrying the national flag. In a warning of the type of thing that we could expect, the Ennahdha party has issued an official note bearing the signature of communications chief Mohamed Nejib Gharbi, speaks of ''persons unknown wearing Ennahdha party epaulets and pennants, who will carry out acts of damage to public buildings''. The alarm raised by the party led by Rached Gannouchi has been echoed by one from Chokri Belad, spokesperson for the Movement of Democratic Socialists, who has also learned of possible infiltrators who will be aiming to attack public buildings, but who will be wearing the insignia of his own party. So there is not only apprehension, but also confusion in the air ahead of tomorrow's march. The Interior Ministry has made it known that police and security personnel will be deployed throughout the centre tomorrow and will not tolerate any violent act from whatever quarter it appears to arise. (ANSAmed).