Housing Department staff vowed yesterday to increase industrial action against plans for privatisation of estate management if job security could not be guaranteed. Over the past month, up to 800 staff, mostly from the middle and lower levels, refused to deal with work relating to yesterday's district council elections. They declined to carry out duties such as approving candidates' applications for holding exhibitions or for visits to public housing estates. They also turned a blind eye to the placing of campaign posters in certain restricted areas. 'These are not our jobs in the first place. They are all extra work. We did them in the past because we were loyal to the Government,' said Lam Man-cheuk, convenor of the Alliance of Housing Department Staff Unions. A government spokesman said there had been no complaints about housing officers' actions concerning the polls. Mr Lam said all the alliance, which represents two-thirds of the department's staff, wanted was a letter from the department guaranteeing their jobs. He said they had been asking for the letter for two years. 'If they keep neglecting us, we will escalate our industrial action. We will stop carrying out some of our duties, such as asking public housing tenants to pay unpaid rentals.' Mr Lam said unionists would discuss the issue on December 8.