The UK 2013 NAP states in relation to New Actions planned that [page 12]:

 The Government will do the following to reinforce its implementation of its commitments under Pillar 1 of the UNGPs:

(vii) Ensure that agreements facilitating investment overseas by UK or EU companies incorporate the business responsibility to respect human rights, and do not undermine the host country’s ability to either meet its international human rights obligations or to impose the same environmental and social regulation on foreign investors as it does on domestic firms.”

The UK 2016 Updated NAP makes no explicit reference to investment treaties or ISDS.