Passport Office workers are beginning a five-week strike in the increasingly bitter civil service dispute over jobs, pay, pensions and conditions.
More than 1,000 members of the Public and Commercial Services union (PCS) at eight sites are walking out in an escalation of the long-running row.
Picket lines will be mounted on Monday outside the offices in Glasgow, Durham, Liverpool, Southport, Peterborough, London, Belfast and Newport in Wales.
