The company said in a statement that industrial action at Maltapost included the non-collection of mail from street post boxes, non-acceptance and delivery of bulk mail and non-delivery of unaddressed mail.
There have also been constraints on the use of telephones and computers. As a result, postal services in Malta have been severely disrupted.
The company also warned that as Union Haddiema Maghqudin (UHM) has issued further directives which may affect Maltapost branches, this could result in a number of branches not opening.
A statement by UHM said the union's directives have been 100 per cent successful.
The union said these directives will remain in operation until an agreement reached on 24 May between the union and management, in the presence of representatives of the Ministry for IT, Technology and Investments is honoured.
This agreement would have increased the number of employees at Maltapost so that present employees use their vacation leave and to relieve the pressure on Maltapost employees due to lack of human resources.
The union claimed that the Maltapost management has not honoured this agreement.
However, a statement by the General Workers Union heavily criticised what it called an "unprofessional approach". As a result of this decision, Josephine Attard Sultana, the GWU public sector section secretary, said GWU members will suffer even though they had not followed the UHM directive.
GWU said it has been informed that only the collectors were obeying the UHM directive while postpersons and administrators were working as usual.
Maltapost's general manager - Corporate Services Joe Gafa, told Ms Attard Sultana that the UHM industrial action affects Maltapost operations.
He added, GWU said, that the whole issue revolves round the lack of post-persons at Maltapost. When the company asked former employees, who had returned to government employment, to come back, they refused because of an issue of seniority and they did not want to go on the beat again.
Furthermore, a number of people sent to Maltapost by Industrial Projects and Services Ltd (former dockyard employees) do not seem to be working out.
For this reason Maltapost is asking the government to permit it to call ETC to recruit personnel. The government, however, is holding out and refusing to allow this. The GWU commented that after having declared that 266 workers were surplus to requirements, the government cannot be expected to admit it cannot operate Maltapost because of a dearth of postpersons.
This shows, the GWU said, how cock-eyed the whole restructuring exercise was. In fact, postpersons have been working in a stop leave situation for a number of months. Ms Attard Sultana said the GWU had long been warning that matters will come to this conclusion. Nevertheless, GWU is ready to negotiate with Maltapost and the government to end this stalemate. However, management maintains that the complement is enough as it is and, since this is a collective issue, Maltapost will discuss it only with the UHM.
The GWU is therefore appealing to all concerned for common sense to prevail.