Arriva have now announced that CAF are to build all of the new units for the Arriva Northern franchise.

http://www.arriva.co.uk/media/news/2016/21-01-2016

31 x 3 car EMU
12 x 4 car EMU
25 x 2 car DMU
30 x 3 car DMU
To be CAF's Civity design

Entering service between October-December 2018