At the weekend I rang an old trade union friend, a veteran of countless public sector negotiations, disputes and occasional strikes, to hear him contradict my own excessively rational view (“don’t do it, comrades”) of the pensions dispute which threatens NHS services this month.

The idea worked a treat. My friend unleashed what he cheerfully admits was an emotional “rant” which started with the democratic nature of Unison’s strike vote – ballot papers nowadays are sent to union members’ homes. It ended with a burst of contempt for the sort of politician and journalist who attacks public servants over strikes, then praises the “heroes” who rescue drivers from burning cars on the M5.

“Talk costs bugger all,” he says.

Like TUC boss Brendan Barber, Unison general secretary Dave Prentis put a brave public face on an awkward tactical situation.

It arose after ministers improved their offer on pension reform – no worse terms for those within 10 years of retirement and an 8 per cent better accrual rate of pension for all – just as Unison’s ballot showed a 78 per cent Yes vote to looming stoppages.

Ministers were quick to point out that the result rests on a 29 per cent turnout among Unison’s 1.3 million members in the health service and local government. Most are low paid and a majority of them women who face average annual NHS pensions of £3,500 (£2,600 in town halls), according to Unison’s (“Fighting for Decent Pensions”) website.

Dave Prentis – and my chum – retaliate. David Cameron’s Tories got 23 per cent of the total electorate, 36 per cent of votes cast in 2010. The government, if we also count the Lib Dems, got 59 per cent of the total on a 65 per cent turnout, but that’s 59 per cent of nearly 30 million. It is a wider mandate than Unison’s 245,358 versus 70,253. We could throw in MPs’ generous pensions here, bankers’ bonuses or top salaries in NHS management. The other side could throw back a few union fat cat pensions too. Cameron gets a five-year mandate, Prentis merely the right to call an eight-hour strike.

“There’s only one word for it – hypocrisy,” says my TUC veteran.

All good fun, which strengthens public indignation and helps cajole bishops into addressing the Occupy St Paul’s activists’ agenda in more sympathetic terms. But it doesn’t solve much. The devil still controls the small print.

My chum is entitled to denounce do-gooders who cross hospital picket lines for the TV cameras, but couldn’t do the job year in, year out. Looking after the sick or attending horrific accidents for 30 years, then getting a £3,800 pension is no picnic, he says.

What about tougher times in the private sector? I asked him. What about the “pensions holiday” private sector employers took in the boom years? he retaliated. What about the thousands who quietly die of cold-related illness every winter?

Yes to all that. It doesn’t magic away the dilemma. Unions are entitled to fight for what their members had been promised. They’ve already made concessions to reflect greater longevity, and now chancellor George Osborne is thinking of reneging on next April’s pensions/benefit rise because September’s CPI inflation rate (not even RPI any more) was a nasty 5.2 per cent!

But that doesn’t solve the government’s fiscal dilemma, a shaky world economy, Greece (and its pensions!) threatening the eurozone, the need to tame the deficit. I don’t assume bad faith among ministers, as I often do with bankers. Let negotiations thrive under pressure. It’s just possible last week’s pensions concession is an implicit admission that Plan A, Osborne’s financial squeeze, was excessive and self-defeating. Let’s welcome Plan B  – and improve on it.