There was disbelief at his description of redundancy compensation as “reward for failure”.

In the Commons debate on second reading of the Enterprise Bill, Sajid Javid MP, said: “Too many public sector fat cats are handed six figure pay-offs when they leave a job, which are often little more than a reward for failure.”

Garry Graham, Prospect’s deputy general secretary, said: “As well as being highly insulting, the Secretary of State’s comments betray a lack of understanding of how his own Bill will impact on the terms and conditions of millions of employees.

“Dedicated public servants earning less than £27,000 a year could be hit by these proposals. Does the Secretary of State really think they are “fat cats” or does he not understand his own measure?

The money paid on redundancy is compensation for the loss of a job that is no longer required to be done, not a payoff for someone who has underperformed.”

Other contributions to the debate were far more promising.

Labour and SNP front bench speakers raised the unfair impact on people on relatively moderate earnings and the application of the cap to employees of companies operated by the private sector.

Some backbench Conservatives MPs also raised their concerns. Conservative party support will obviously be key to securing amendments to the Bill.

Dr Julian Lewis, the MP for New Forest East said: “I am aware of concerns raised not only by the Prospect union but by one of my constituents about the fact that as someone who has always earned less than £28,000 a year, he may, as a result of early retirement, be unintentionally caught by this provision. I hope we will get some assurance from the Government Front Bench either that that will not happen, or that an amendment will be accepted to make sure it does not happen.”

In a blog post about the Bill, Ian Liddell-Grainger, the MP for Bridgwater and West Somerset, said his constituents working for Magnox Ltd should not be impacted by the proposed cap.

“I think the Government has got it wrong and I am fighting to get them excluded from the impact of the Bill.”

Many other MPs indicated support for the issues with the Bill Prospect believes should be rectified. Prospect will continue to work with other trade unions to lobby MPs and it will also submit evidence to the Bill committee.