Tens of thousands of people Monday marched through the streets of Rotterdam, the world's largest port, to protest at the Dutch government's planned social security and health sector reforms.
The city's dockers went on strike for the day as did public transport workers in Rotterdam and The Hague.
Trade unions said 60,000 people marched against the government proposals on the eve of the presentation of 2005 budget. Individual police officials quoted the figure of 30,000 but police headquarters declined to give an estimate.
The ECT container transit firm in Rotterdam has been virtually paralysed since Sunday evening.
Only a handful of administrative and security staff were working, company director Jan Gelderland told the ANP press agency.
Around 1,000 teachers in the Rotterdam region, along with hospital and museum workers, have said they will also take industrial action Monday.
The unions are opposed to measures by the government of Prime Minister Jan Peter Balkenende aimed at reducing early retirement entitlements, putting back the retirement age and reforming the social security contributions system from January 1, 2005.
An opinion poll commissioned by state-run Dutch radio indicated that more than 60 percent of those questioned were opposed to the reforms presented by the centre-right government combining Christian Democrats, Liberals and centrists.