Police called for calm yesterday as supporters and opponents of national education began gathering for a showdown outside government headquarters. Thousands of protesters were expected in the square outside the complex in Admiralty, where the two camps were separated by fences and policemen amid fears of clashes. The group in support of the curriculum - the China-Hong Kong Federation of Youth Culture - called on supporters to dress in white, and expected 1,500 people. The Civil Alliance Against National Education, which encouraged its participants to wear black, said about 4,000 would attend. Early yesterday evening the number of opponents came to about 800, while supporters had less than a quarter of that. Police said officers would take "appropriate measures" to assist the demonstrations and appealed to participants to express their views in a peaceful and rational manner. The force said it had suggested the groups change the venue, but no consensus could be reached. Two organisations were in charge of the demonstration in support of the curriculum, but the police said on Tuesday that one had pulled out. The alliance against the curriculum said the arrangements could add pressure on front-line policemen as conflicts could arise from the overlapping sounds of the two broadcasts. "We announced that we would be back on the 17th, and the other party announced the next day, and applied for the same spot, with basically the same agenda," Joshua Wong Chi-fung, convenor of student group Scholarism, said. "We do worry there might be clashes between the groups, and ultimately, it would be tough on the police." The group described last night's demonstration as "a return to the civic square", just one month after its 10-day siege of the government headquarters ended. Organisers decided to disperse last month after Chief Executive Leung Chun-ying announced that a three-year deadline for compulsory implementation of national education would be scrapped. The government further backed down last week by shelving the scheme's controversial guidelines, following recommendations from the Committee on the Implementation of Moral and National Education. On the supporters' side, a student from St Joseph's college said he did not like the way Scholarism handled the issue. "I think that there is still much room to negotiate on how national education will be," said Form Five student Jason Lee. "They are just against it for the sake of being against it." A Mr Tam said he supported national education because he thought the other side was "taking away my freedom to have national education". "I don't believe it's so easy to be brainwashed," he said referring to the claim of opponents that the curriculum amounted to brainwashing. "Their minds may be simple, but mine is not." Admitting he had not looked at the guidelines, he said: "I don't need to know what the national education guidelines say, I just know that I should be free to have it."