Devolution will boost stagnant productivity in the UK public sector, according to a former MP and ex-adviser to Treasury chief secretary Danny Alexander.

Julia Goldsworthy, who spent four years at the Treasury and is a former Lib Dem MP for Falmouth and Camborne, wrote in a new Demos publication: ‘The relative strength of the public sector's ability to attract and progress a skilled workforce does not appear to have translated into increased productivity.