A question that came up on a forum recently; If you were to turn right here onto the dual carriageway, would you be able to position half way if was clear from the right, but traffic to the left?
These were the answers that best suited the question.
Yes there is enough room to sit in the central reservation, treat this as 2 separate junctions.
As long as nobody from the left is approaching to turn right, you can move to the middle and wait for your opportunity. By ensuring nobody is approaching to turn right from the left before moving to the middle, you're not pulling out into anyone's path.
Remember your actions should not 'cause' any other road user to slow, swerve, or stop.
If THEY 'chose' to do so to allow you to complete what you are doing then that's ok, however if you only leave them with that choice then it's not.
Looking at the google map it’s dual carriageway on the first section, then just passed the central reservation the road is a single carriageway.
If you moved over to your right hand side (as you move across the dual carriageway) it looks like plenty of room (as long as your not towing anything) to sit and wait rather than waiting for both sides to be clear.