Disco 3 (LR3) Tow bar stuck

So I've got a new Disco 3 and the removable tow bar is stuck. The red key turns but the green unlocking knob won't turn - any ideas?

lubrication

aside from that, check if the recall work's been done

https://www.lro.com/blog/news/land-rover/1509/faulty-tow-bars-mean-major-land-rover-recall

Thanks - want to get the blimmin' thing off first so I can have a gander.

Look on the bright side no fcuker can nick it!
Even when new they can be tight.
I think the recall was for the tapered bit being loose in the receiver due to wear/freeplay, so if its stuck.

Well worth looking into spare wheel security as easy to nick.

Thanks lynall, the tow bar is sloppy at the moment to say the least so need to be able to remove it to fettle it and see if its engaging properly. Will have a look at the the spare wheel too

I reckon its duck oil/wd40 time, first few times I used mine it was bloody hard to get out.
Might pay to leave it in as it is and take for the check stating that you do lots of heavy towing and I think you might get fox a new fixed towbar set up as they now say the demountable type is for occasional use.

When I was happy with the fit I copied a design from the D3 forum which holds the towball hard into the socket and makes it much harder to steal.
If you look on ebay theres always an endless supply of used/reconned towballs for sale.

Have a read, I copied the drawings the guy supplied, his was laser cut and mine was crude and made with a grinder with thin slitting disc, didnt take long to make and is vey secure once bolted up.
You might have to join the forum to see the pics, but worth while as full of info.

http://www.disco3.co.uk/forum/topic104348.html

Thanks very much lynal, that's really helpful. I'm on the dico3 forum, looks pretty straightforward - I might just have a bash at making one.
Managed to get my stuck towbar freed off, all fettled and copper slipped now so works fine.