Term derives from the jobsworth mantra "I can't let you do that, it's more than my job's worth".
Jobsworth behaviour can also maniest itself in someone more senior who anally keeps to script on every task and project, often based around analysis and control of other people's work Risk Management, Issue Analysis for example), and who uses the phrase "As we have discussed" and "Further to our conversation yesterday, you agreed...", copying in their and your manager 'for reference' when in reality it's to cover their back should anything go wrong, thus meaning they will not take any responsibility and you'll be left looking like a mug.
"The frigging jobsworth totally stitched me up. He pulled up some long email trail but didn't even mention that I'd told the jobbo twat on Thursday I wouldn't be able to finish it in time because of the accident with the lawnmower"
"A council spent £5,000 planting yew trees to screen a new children's play area. It then dug them up again after health and safety experts advised children could fall ill if they gobbled 'several handfuls' of leaves." - Jobsworth #2