Hongkongers should boycott the pan-democrats' attempt to trigger a de facto referendum, and the government-friendly camp should not take part in by-elections triggered by the resignation of five pan-democratic lawmakers, a mainland drafter of the Basic Law said yesterday. Professor Xu Chongde said the five legislators from the Civic Party and the League of Social Democrats were wasting taxpayers' money trying to fulfil their 'selfish' plan. 'The Basic Law has an established procedure to change Hong Kong's political system,' he said. 'Their attempt to trigger a de facto referendum violates the Basic Law.' Xu said the lawmakers who resigned on Tuesday should not attempt to regain their seats through by-elections. 'Legco is not an amusement park where people can come and go as they like,' he said. Xu, a law professor at Renmin University in Beijing, said the pan-democrats had not done anything for Hong Kong's prosperity and stability. 'What they have been doing over the years are attempts to stir up trouble,' he said. Two weeks ago, the State Council's Hong Kong and Macau Affairs Office said that any 'so-called referendum' would be inconsistent with the city's legal status and a blatant challenge to the Basic Law and the central government's authority. Xu said responsible political groups should not take part in the by-elections. The Liberal Party decided on Saturday not to contest the polls. The Democratic Alliance for the Betterment and Progress of Hong Kong did not make a decision at a meeting of its central committee on Tuesday. DAB lawmaker Ip Kwok-him said the party would not make a decision this week. 'We haven't made a decision so far because we would like to observe how things unfold in the near future,' he said. He said there was no need to make an irreversible decision at the moment, but admitted the chance of a candidate from his party standing in a by-election was slim. Lau Nai-keung, a member of the Basic Law Committee, said Beijing had reacted strongly to the pan-democrats' attempt to trigger a de facto referendum because it touched upon a crucial principle, and there was no room for compromise. 'Only sovereign states are empowered to conduct referendums,' he said 'If a de facto referendum is allowed in Hong Kong, what happens if people in Tibet and Xinjiang call for a referendum on whether they should declare independence?' Lau said Beijing was worried that the pan-democrats would attempt to trigger such referendums whenever they were unhappy with other issues. 'Today they want a de facto referendum on universal suffrage; tomorrow they may demand another one on amendments to the Control of Obscene and Indecent Articles Ordinance. If these kind of sagas keep on happening, we might have by-elections on 180 out of 365 days.'