Passport Office workers will begin a five-week strike today in the increasingly bitter civil service dispute with the government over jobs, pay, pensions and conditions.
More than 1,000 members of the Public and Commercial Services union (PCS) at eight sites will walk out as the long-running row continues to escalate.
There will be picket lines outside offices in Glasgow, Durham, Liverpool, Southport, Peterborough, London, Belfast and Newport in Wales.
The union said those walking out will be supported by a strike fund.
PCS general secretary Mark Serwotka has written to the government calling for urgent talks in a bid to resolve the dispute.
He has accused ministers of treating the union’s members differently to others in the public sector after negotiations were held with unions representing health workers and teachers, leading to improved pay offers.
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The PCS is stepping up strikes, with a nationwide walkout of more than 130,000 civil servants planned for 28 April.
The Home Office said the Passport Office has already processed more than 2.7 million applications this year.
It added over 99.7% of standard applications are being processed within 10 weeks, with the majority of those delivered to customers well under this timescale.
There are currently no plans to change official guidance which says it takes up to 10 weeks to get a passport.