Fylde civil servants walked out as part of national strike action in protest at moves they fear could see their jobs transferred overseas.
Around 250 staff who work for Shared Services, part of the Department for Work and Pensions, based at Tomlinson House, Norcross, could be affected by the changes.
Several workers formed a picket line between 7am and 9am yesterday as the national action started.
The action had been called by the PCS civil service union which warned if the Government sells the department to French company Steria, it could mean the loss of work overseas.
Shared Services handles sensitive information including payroll and procurement details.
Branch secretary of the PCS DWP Fylde Central Benefits and Services branch Duncan Griffiths said: “There are about 250 people impacted by the privatisation at DWP Norcross, Tomlinson House.
“There have already been over 3,000 jobs lost in the DWP in the Fylde area over the last few years.
“We have raised our concerns about the jobs situation with MPs and other political leaders over several years.
“The area is crying out for jobs, not more uncertainty.
“We have made a case to the MPs that DWP Norcross should be used as hub for Civil Service work, rather than bulldozing the majority of the site as is planned in the near future.”
Around 1,200 staff nationally took part in the strike, which also affected offices in Cardiff, Newcastle, Sheffield and York.
A Cabinet Office spokesman said: “It is disappointing that yet again the PCS insist on pushing for futile action which benefits no one and damages the services they deliver to the public.
“The Civil Service is moving to be faster, smaller and more unified and sharing services is a central part of this. The Next Generation Shared Services Strategy sets out a new model to share HR, procurement, finance and payroll functions with five centres instead of the current eight in order to deliver more efficient and cost-effective services for the taxpayer.
He added: “We have begun the process of selecting a private sector joint venture partner for the second of the two independent centres and are consulting with staff and unions.
“We will make an announcement in due course.”