On 7 September The Times reported on consultation taking place between UNISON and union empoyees on proposals to safeguard the staff final salary pension scheme (http://www.timesonline.co.uk/tol/money/pensions/article6824024.ece)
If the union was abandoning or closing its scheme like 70% of private sector employers (or certain other unions) then there may have been a point in the story or a justification for a disloyal employee leaking internal documents to an anti union newspaper.
The facts unreported by the Times are that the union is working closely with the staff unions to maintain a quality pension scheme open to all union employees, who will be balloted on any new arrangements. A senior official of the UNISON staff unions commented in a headline report on the Professional Pensions website:
"The trade unions, who represent UNISON staff are concerned at the pension scheme deficit and have been working with UNISON's management on measures to address it. We recognise that UNISON's pension deficit has increased in recent years, as have most, if not all, employers' final salary scheme. We have had very thorough and productive dialogue with UNISON over recent months on creating measures to meet the deficit, while continuing to maintain a robust final salary scheme." (http://www.professionalpensions.com/professional-pensions/news/1532668/unison-considers-db-scheme-changes)