The Government has been accused of using misleading figures in an attempt to manipulate public opinion in the debate over public sector pensions.
The accusation came from Britain's largest union, Unite, which said that Chief Secretary to the Treasury, Danny Alexander, had made the "extraordinary claim" that under the Government's proposed scheme a nurse with a full career retiring on a salary of £34,200 would receive a pension of £22,800 per year, instead of receiving only £17,300 under the current system.
Unite carried out an analysis of the claim, and said that Alexander's example was based on a comparison of a nurse working for 43 years and retiring at age 68 in the proposed scheme and a nurse working for 35 years and retiring at age 60 in the current scheme.
Unite said that the proposed scheme involves public sector employees working and contributing for eight years more and receiving the pension for eight years less.
Unite also accused Alexander of failing to mention that public sector workers will face a 50% increase in their contributions.
Assistant general secretary Gail Cartmail said: "Danny Alexander is making extraordinary claims in order to mislead and manipulate the public about the Government's pensions proposals.
"He's using distorted figures to conceal the way in which government proposals will reduce pensions. Most NHS workers will not get a pension anywhere near this maximum full-time service example and many will have lower pay than the qualified nurse he has focused on, but all will suffer similar proportionate losses to those he is trying to conceal. Currently the average (median) pension received by NHS workers is only around £4,087.
"The unions are telling the truth when we say the Government wants public sector workers to pay more, work for longer and retire on less. We are prepared to negotiate using the facts. It is time the government dispensed with the dirty tricks and negotiated properly."
However, a Treasury spokesman described Unite's claims as "obfuscation" and supported the calculations referred to by Alexander, stressing that the Government had been transparent and upfront about the fact that public sector workers will need to work longer and contribute more to their pensions.
He said: "We absolutely stand by everything Danny Alexander has said. We have been absolutely crystal clear - people will be working longer and contributing more than they were before.
"We stand by our calculations, which were based on independent calculations by the Institute for Fiscal Studies, and where we have based them on a full career, our calculations are correct.
"Everything we have said has been totally transparent and we challenge anyone to find anything misleading in the proposals."
He added: "As many objective observers have noted, we have made a generous offer and set this out in unambiguous terms. Those more than 10 years from their retirement age will have to work a bit longer and those earning more than £15,000 will have to pay a bit more. But if you are on a low or middle income you will get at least as good a pension, if not better, than you get now. To get the same pensions from the private sector you would need to pay around one-third of you salary every year, considerably more than under the Government's offer."