The authorities have signalled a harsher line towards 'bourgeois-liberal' elements by cancelling a meeting to salute the achievements of famed economist Yu Guangyuan . Mainland sources said yesterday that friends of Mr Yu had intended to hold a conference on December 22 to mark the scholar's 60 years of contribution to Marxist research. More than a dozen academic units were involved in organising the meeting, which was set to take place at a restaurant and function centre under an official trade union department. They included China Research Society on Natural Dialectical Materialism; China Research Society on Technology and the Economy; the China Literature Foundation; and the Shanghai Economic Development Research Society. However, a couple of days before the conference, the organisers were told by municipal authorities that owing to a 'potential fire hazard' at the venue, the event had to be cancelled. It is understood that Mr Yu, who had advised former party chief Hu Yaobang , failed to get a further explanation from the authorities. The 81-year-old scholar, noted for his advocacy of radical market reforms, later left for a conference on Hainan Island. 'The ban on the meeting was a big blow to the morale of liberal cadres,' a Beijing source said. 'Conservative leaders in the party were involved in the decision. 'They wanted to teach a lesson to intellectuals who had criticised Beijing's recent embrace of quasi-Maoist norms.'