The Public and Commercial Services union (PCS), which has members across Portsmouth, is holding a consultative ballot over the cost of living crisis.
Another ballot would have to be held before any industrial action takes place.
The union, which represents workers in the civil service, including government departments, said it has made several demands, including a 10 per cent pay rise, a cut in the working week, and reduced pension contributions for its members.
Voting will start today and run until March 21.
Mark Serwotka, PCS general secretary, said: ‘Civil service staff who have kept the country going throughout the pandemic have suffered over a decade of real terms pay cuts and declining living standards.
‘It is a gross injustice that members have had their pensions robbed and are expected to pay for ministers’ mistakes.
‘This ballot is an opportunity for our membership to tell us whether they are willing to strike, and PCS will support them every step of the way.’
The ballot follows the news that 900 Portsmouth jobs at the tax office at Lynx House in Cosham would be saved after HMRC announced its decision to open a new regional centre in the area - a decision welcomed by the Portsmouth Public and Commercial Services (PCS) union branch.