It looks like a nasty case of mildew, which can be caused by the honeysuckle being too dry at the roots, or too much rain.
Try spraying with one part milk to nine parts water every two days until the greyness is gone. The yellow leaves will not recover, and will eventually fall, so give the plant a good feed to encourage new growth.
Thank you advice much appreciated.
Gave my overgrown honeysuckle a short back and sides last year as it was getting too woody. Pleased to say this year masses of new growth and flowers. Have never fed it except with a bit of what comes out of the compost bin each year. Dont think we have to worry about them not getting enough water this year.