The department has made an offer which is based on reducing terms and conditions for staff.

Almost half of the three-year offer needs to be funded by reducing overtime payments, removing the London pay lead and changing how allowances are paid, reducing their value. The impact will mostly be felt by the lowest paid staff in the department.

Prospect believes the offer will lead to recruitment and retention problems and that outputs will need to be met by overtime which nobody will volunteer for if it is paid at single time.

“As well as cutting the take-home pay of the lowest-paid staff, the offer is divisive and damaging to the department’s output.

“The overtime proposals have clearly been drafted without knowledge or understanding of how overtime operates across the department,” said the union’s negotiator Julie Flanagan.

Until Tuesday 5 November, Prospect and the other unions believed they were close to agreeing a three-year deal worth 3% a year to all staff.

It would have been a mix of consolidated and non-consolidated pay depending on the relationship with grade pay maxima and minima.

The unions were due to meet the department on 5 November to develop this further.

When they arrived, the permanent secretary told them that the department was publishing an offer that the unions had already rejected.

If they didn’t accept it, the fallback would be the 2% figure in the Cabinet Office pay guidance.

Prospect and the other unions have made it clear both verbally and in writing that the entire offer is unacceptable.

“The department’s approach to negotiations is in extremely bad faith.

 “We will not trade members’ terms and conditions to fund pay rises and the proposed changes are fundamentally flawed.

“The permanent secretary’s belief that staff will welcome this offer and be prepared to sell their colleagues’ terms and conditions down the river for this pay rise is misplaced,” said Flanagan.

The unions will formally reject the offer and ask the department to return to the negotiating table in good faith and complete the discussions they had almost concluded on the three-year deal.