The Public and Commercial Services (PCS) union, representing workers at the Home Office and Border Force, said demoralised staff fear being forced to break the law and could “explore” industrial action.
But senior Tories said a threat to walk out over the key parts of the government’s asylum policy was “appalling” and “unacceptable”.
Jacob Rees-Mogg – who has claimed a left-wing Whitehall “blob” is out to thwart the government – said staff going on strike over policy would amount to quitting their jobs.
The former cabinet minister said: “Refusing to carry out the policy of the elected government is not going on strike but resigning. A politically impartial civil service must carry out lawful policies.”
Former home secretary Priti Patel also condemned the idea of strike action, insisting the civil service must “respect the policies and legislation of a democratically elected government”.
Ex-justice secretary Robert Buckland – a Tory moderate who has been critical of some aspects of the small boats bill – joined right-wingers in warning against walkouts. “If the policy is lawful, it is not for civil servants to strike or refuse to cooperate,” he said.
Home secretary Suella Braverman’s highly controversial Illegal Migration Bill aims to detain and deport all asylum seekers and modern slavery victims who arrive on small boats without considering their claims. The UN Refugee Agency said in March that the plans were a “clear breach” of international law and “amount to an asylum ban”.
Ms Braverman has said it is her “dream” to see small boat arrivals deported to Rwanda, but the scheme remains mired in ongoing legal action.
The PCS’s head of bargaining Paul O’Connor told The Independent the union had already joined legal action against the Rwanda deal, and was “ruling absolutely nothing out in terms of responses”.
The union said members were buckling under “political pressure” and fear of being forced to break the law. “If any litigation fails, they will want to explore with us whether there’s an industrial solution,” said Mr O’Connor.
Mr O’Connor also said the Tory government’s agenda was damaging some civil servants’ mental health. “They feel if they were put in a position where they had to carry out an act that was subsequently proved to be unlawful, they themselves might be open to prosecution.”
One asylum caseworker at the Home Office told The Independent that “many” colleagues would strike if given the opportunity. “The main factor is the fear of being told to do something illegal, doing it, and then facing consequences. There are also serious mental health concerns over these new expectations,” they said.
But senior Tories insisted staff had no reason to be wary of implementing asylum policy – claiming civil servants were in the “wrong job” if they wanted to take a political stance.
Former Tory minister David Jones, who is the deputy chair of the European Research Group, said: “They can’t pick and choose between policies.”
“The policy doesn’t appeal to those of left-wing disposition. So it’s not a question of law, it’s a political stance – and that’s acceptable. They’re in the wrong job.”
Martin Vickers MP, a senior figure in the Tory Common Sense Group, said: “I’m appalled. Civil servants sign up to the job to implement government policies. It’s not for an individual to decide if something’s unlawful.”
Former Tory minister Andrea Jenkyns added: “Civil servants are expected to serve – not govern. That is the job of the elected government, who has a mandate from the British people to reform human rights and bring together illegal immigration to an end.”
Mr O’Connor said the PCS could ballot for strike if opposition to the government’s plans escalates into a trade union dispute, centred on how new migration policy affects civil servants’ terms of employment and working conditions.
But a former senior Home Office civil servant said they were “pretty sceptical” that opposition to the policies, or fears of unlawfulness, would be lawful grounds for strike.
Mr O’Connor said that civil servants were also “sick of being used as a political football”, amid frequent accusations from senior Tories that they are part of a politically motivated “blob” obstructing government policy.
“What is happening in reality is that ministers don't like the advice that they’re getting and are therefore trying to portray that as some kind of nefarious plot,” he added. “They just need to look in the mirror at their own ineptitude, that’s what's at the root of it.”
The High Court ruled the Rwanda policy lawful on principle last year, but overturned all decisions made against individual asylum seekers. The judgment is now being reconsidered by the Court of Appeal, and Ms Braverman has subsequently expanded the scope of the agreement to include modern slavery victims.
The Rwanda challenge was backed by the PCS, and it also wrote a letter to Home Office permanent secretary Matthew Rycroft saying members believed measures in the new small boats bill were outside the “confines of the law and international treaties the UK is a signatory of”.
The PCS has backed a “safe passage” policy that it argues would cut demand for people smuggling by allowing asylum seekers to apply for UK visas using an online screening process.
A Home Office spokesperson said: “Our staff work tirelessly to deliver ground-breaking policies, such as the Illegal Migration Bill.”
They added: “We have always maintained that the UK and Rwanda Migration and Economic Development Partnership is lawful, including complying with the Refugee Convention, and last year the High Court upheld this. We stand ready to continue to defend the policy against legal challenge.”
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