The leader of the largest civil service union has blamed permanent secretaries for the failure of negotiations over proposed changes to civil service redundancy payouts.

Speaking to Civil Service World, the general secretary of the Public and Commercial Services Union (PCS), Mark Serwotka, said that Cabinet Office minister Tessa Jowell has been “poorly served” by permanent secretaries, who he claimed have failed to engage with the union in negotiations.

Serwotka, whose union broke with other civil service unions to reject the Cabinet Office’s proposed changes to redundancy payments last week and is now planning strike action, complained that there was only one, informal meeting between management and the unions between last September and renewed negotiations in the new year.

“I have no doubt that their lack of engagement was a deliberate attempt to ensure we didn’t reach an acceptable arrangement,” he said. “I’ve made that point myself to Tessa Jowell: she was not very well served by permanent secretaries.”

Serwotka singled out Department for Work and Pensions (DWP) permanent secretary Leigh Lewis for particular criticism, saying the DWP boss had a “very old-fashioned view of industrial relations”.

The Cabinet Office announced last week that it had secured agreement on changes to civil service redundancy rights with five of the unions that make up the Council of Civil Service Unions (CCSU): Prospect, the FDA, the GMB, Unite and the Prison Officers’ Association – but not the PCS. The government believes the changes, applicable from April, will save £500m.

The altered scheme, first mooted last July, leaves the majority of officials with smaller payouts for compulsorily redundancy. The maximum payment for a lower paid worker will be capped at £60,000 or 24 months’ pay, whichever is lower.

PCS, which represents 270,000 mostly junior officials – compared to the 100,000 employees represented by other CCSU members – now plans disruptive strikes in March over what Serwotka described as “a provocative act that most people think is about making it easier to get rid of people en masse after the election”.

Serwotka said his members are “very angry”, and he’s planning the largest ever civil service industrial action. He called for negotiations to be reopened directly with ministers.

However, other unions reject the PCS position. Jonathan Baume, head of the managers’ union the FDA, claimed the deal is an improvement on the terms previously offered to the unions, and contains protection for staff earning under £20,000 – a category that, he said, includes the majority of PCS members.

“We think it is the best possible deal we could get, and a deal which is still on a par with the rest of the public sector and offers significant protections for a great many serving civil servants,” Baume added.

In the wake of the high-profile CCSU split, Serowtka complained that the “acquiescence” of other unions was being used by the Cabinet Office to undermine the PCS’s planned strike action. “If I was in those unions I would be thinking quite long and hard about that situation,” he said.

“All those unions combined are a third of the size of PCS; quite clearly, we are the union that the Cabinet Office really should be concerned about.” Baume said he was “disappointed” that the PCS had attacked other unions, suggesting that Serwotka’s stance implies that “no one should have a say other than the PCS.”

The PCS strike ballot runs until February 26. Cabinet secretary Sir Gus O’Donnell last week described the planned action as “wholly misguided”, but 141 backbench MPs have signed a Commons early day motion in support of the union.