A vote by members of the Public and Commercial Services Union in favour of action could result in a strike by up to 150,000 workers across government this summer.
PCS general secretary Mark Serwotka said: “It is astonishing that the government singles out its own hard-working and committed staff for a derisory 1% rise when they have rightly offered higher pay rises to other public sector workers.”
In talks with PCS leaders on Wednesday, the government signalled that pay rises would have to come from individual departmental savings and cuts.
Serwotka said: “Our members feel misled and betrayed because assurances were made by ministers that the 1% pay policy was ending and that money would be found to reward staff for their hard work.
“However, officials admitted they were using spending budgets from three years ago, despite finding money for all sorts of other issues since 2015.”
The topic was also raised in parliament on Tuesday by the chair of the PCS parliamentary group and SNP member Chris Stephens.
He said: “A few months ago the government declared – to great fanfare – that the public sector pay cap had been lifted, but is that really the case?”
Stephens said that in May he asked the prime minister to confirm that the government had budgeted for a 1% pay rise for civil servants.
Theresa May said in response: “We have been very clear that the blanket 1% cap that has taken place over recent years on public sector pay is not an approach that we are taking in the future.
“Obviously, departments are funded at a certain level, and it is for departments then to come forward with their proposals in relation to pay within their department.”