Commonwealth Bank chief executive Matt Comyn says income tax for workers earning less than $300,000 should be cut to 30 per cent, the GST increased and the tech giants slapped with a levy as a key reform to revive economic growth.

Urging the government to overhaul the tax system in a self-described “blunter” fashion, Mr Comyn said turning around a forecast slowdown in long-term economic growth had to focus on “international competitiveness, dynamism and supporting both the mobility of labour and capital”.