A number of British companies took part in the competition, but none submitted a final bid for the build contract. In light of this, the best option for Defence, and value for money for taxpayers, is for the tankers to be constructed in South Korea by DSME.
Thoughts here are
The UK Shipbuilding industry has its order books full
The UK Shipbuilding industry isnt prepared to suffer HMG imposed delays ala CVF
The UK Shipbuilding industry couldn't come up with a low enough bid.
or the most plausable reason
HMG is sending a waring shot over BAE Systems bows