An earlier delegation left last week after being threatened with deportation, and the new arrivals face the same consequences if they address rallies and hold press conferences.
They arrive as the dispute is winding down, at least for now. After nearly a month of national strikes, hundreds of thousands of South Koreans will work normally today in an unexpected change of tactics.
Officials of the illegal Korean Confederation of Trade Unions (KCTU), which has co-ordinated the stoppages and demonstrations against a revision of labour legislation, have dropped their demand for the scrapping of the new laws that make it easier for companies to sack employees and postpone the right freely to form unions. But they insisted that they were not stepping down. The KCTU's leader, Kwon Young Gil, said that it would resume an "all-out struggle" if the government failed to revise the legislation by 18 February. Until then, strikes will be limited to Wednesdays, with demonstrations every Saturday.
The three-week strike is estimated to have cost South Korea more than $3bn (pounds 1.8bn) in lost production and exports, but it had been losing momentum since last Wednesday when a general strike call by the KCTU and the bigger, official Korean Federation of Trade Unions (FKTU), achieved a patchy turn out. Union officials speak of the need to "conserve energy", and to capitalise on the widespread public disapproval of the new laws and the way in which they were secretly pushed through by the government of President Kim Young Sam.
According to Korean journalists, opinion polls showing plummeting levels of support for Mr Kim have been suppressed. But even members of Mr Kim's own New Korea Party (NKP) acknowledge that his popularity has suffered and the political consequences are likely to be damaging.
Fierce protests continued in Seoul over the weekend, and several marches and rallies were broken up by police firing tear gas grenades. An unknown number of students were injured when police retaliated against attacks with petrol bombs and iron bars by charging and beating up protesters. On Saturday, a march of as many as 10,000 people was led through the city by a group of Christian clergymen.