Less than half of the Social Security Agency's staff took part in a half-day strike on Wednesday, its managers have said.

The public service union NIPSA organised the action because it said workers were unhappy at plans to extend opening hours to the public from 1530 to 1630.

The action began on Wednesday afternoon when some staff walked out of social security offices across the province.

But an agency spokesman said that 1,100 of the agency's 2,300 staff took part in the strike.

He said about 60% of workers stayed at their desks and 19 out of the 35 offices stayed open.

NIPSA said an overtime ban would be introduced on Thursday as an extension of the action.

Tony McMullan NIPSA: "Our members are not prepared to take on additional work"

Tony McMullan of Northern Ireland Public Service Alliance union said the Social Security Agency's management had been inflexible in their approach.

He said: "Management were refusing to provide any additional resources in order to cope with this extra workload.

"And obviously our members are not prepared to take on additional work and as well as that to forgo the opportunity to be able to work the flexible working hours scheme."

But the agency said the changes were to put it in line with other public sector services and would not increase the workload of staff.

'Inappropriate'

SSA personnel director Tommy O'Reilly said: "Staff are being asked to extend the time they spend with the public, not to work any extra hours.

SSA personnel director Tommy O'Reilly: "No change in conditions"

"They are not having their terms and conditions changed. Staff have always been required to work normal office hours.

"It is disappointing that NIPSA has decided to advise their members towards this inappropriate action.

"Social security customers are entitled to a service at least comparable to the services received from other public sector organisations.

"Most other public sector organisations open their public offices to at least 4.30pm. Social security customers should expect this at the very least."

Another agency spokesman added: "The issue of extending public office hours to 4.30pm is not new to NIPSA representatives, it has been the subject of consultation for the last 15 months.

"In that time NIPSA has not raised one legitimate objection to the Social Security Agency improving customer services this way."

The Social Security Agency employs 2,300 staff in its public offices and 6,500 in total across Northern Ireland.