Thanks to those who replied. I am suitably shamed. The axle was indeed seized inside the hub.
Tried a cargo strap around the fork legs but couldn’t get it low enough due to the rotor being in place.
So I undid the axle which continued to push the LH form leg out, until I heard a click that the last thread on the axle had unscrewed. I then took a rubber mallet and gave the LH dropout a couple of sharp whacks, which had the desired effect, allowing me to pull out the axle with pliers. The cause was then obvious, two bands of rust the tell tale signs.
Lesson learned the axle was cleaned up with steel wool and copiously greased before reassembly.
Cycle mechanic zen wasn’t with me last weekend. The next disaster to be overted was cleat removal with a rounded bolt head, requiring the cleat to be hack sawed through.
Cheers