The immigration system could be plunged into administrative chaos in January, with 2,000 interpreters threatening to refuse to work due to pay cuts.
The dispute centres on an email sent to interpreters in November saying their pay rate for their first hour's work – which is enhanced to cover the cost of travel – would be significantly cut.
They also claim they have not had any pay rise since 2002, meaning wages have fallen significantly in real terms.
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They are tasked with travelling to immigration centres to deal with asylum seekers and others who need translation services to help them interact with the Home Office.
As they are not salaried workers, the interpreters cannot go on strike, but they can refuse to take assignments. What's more, there is no ready pool of replacements, meaning any boycott would seriously hamper the immigration system.
One of those organising the possible boycott, who opted to remain anonymous, told the Guardian: “At the moment, the Home Office needs interpreters more than we need them. They do not have any other system currently in place to substitute our services other than for telephone interpreting, which they can outsource.
"They know that if we boycott even for a day, that will cause major disruptions to their business," they added.
A Home Office spokesman acknowledged the discontent, saying: "We are aware some interpreters have raised concerns about this and we have met with them to discuss why the changes are necessary.”