TENSION between social work assistants is expected to rise today as strikers return to work, rejoining colleagues who had worked through the three-day protest over pay. Morale began to deteriorate when some workers said they wanted to give up halfway through the dispute, which ended last night. One protester became so disillusioned he resigned from the social work assistant branch of the Hong Kong Chinese Civil Servants' Association. A source within the Social Welfare Department said the association seemed to have painted itself into a corner. ''I think there are a lot of people who are now saying they believe they went too far,'' the source said. ''I believe they may now be looking for a way out, and from our point of view I think [Director of Social Welfare Ian Strachan's] proposals to sit down and talk rather than confrontation is the right way ahead.'' Juvenile correction institutes, rehabilitation centres and homes for the elderly were among more than a dozen institutions affected by what was effectively a sit-in. Social work assistant branch chairman Lai Wing-shing claimed much of the tension was provoked by the department. ''Some [protesters] have been warned about issues of pay and promotion,'' he said. ''Seven members tried to withdraw from the protest but stayed with us in the end. One was adamant he wanted to stop and resigned his membership.'' Mr Lai also claimed managers at many centres where the disputes took place prevented telephone calls between him and his members. ''We were unable to contact them [members] until they went home. They couldn't receive any calls from us and couldn't make any.'' He said he could envisage problems at work today with many social work assistants being embarrassed about the protest. But he added: ''In a protest like this there are bound to be problems, but we must stand up and fight for justice. ''At the end of the day we are fighting for a better deal for all the social work assistants.'' A department spokesman described Mr Lai's claims of intimidation as ''childish''. ''I get the impression Mr Lai is getting desperate,'' she said. ''Last week, the department offered to set up a task group to look into their claim, then he decides to take industrial action.'' Mr Lai has threatened ''more drastic'' industrial action, including possible full strike action, unless the department meets their pay demand within a month. Social work assistants want a pay increase from their present monthly minimum of $18,205 to $20,905, because they claim to be better qualified than senior welfare workers who earn a monthly minimum of $19,695. Mr Strachan, who said the pay structure was based on other factors as well, such as experience, will meet association members today, at a meeting that was scheduled before the industrial action began. ''We must try to find a case based on logic which will allow us to go back to the branch with proposals,'' he said. The association claimed that most of its 251 memberstook part in the dispute. The department put the figure at 120.