The firm is a signatory to a letter published in the Times newspaper on 20 October. Jonathan Riley, head of tax, Grant Thornton UK, has signed up along with Stephen Herring, head of taxation, Institute of Directors, and a dozen other high profile representatives of entrepreneurial activity.

The letter states: ‘Few areas are in as urgent need of reform as our excessively complex tax system, which does not sufficiently distinguish between SMEs and multinationals or recognise the impact of small businesses on job creation.’

The text argues that while the UK ‘is a great place to start a business’, with more than half a million founded last year, the number that succeed in growing significantly is still relatively small.

The letter concludes: ‘The chancellor’s Autumn Statement in November must be far-reaching. To enable domestic growth and the UK’s global ambition we must modernise or replace business rates, simplify compliance with corporation tax and maximise the benefits of tax reliefs for companies that are creating employment. Anything less would be a missed opportunity as we rewrite our role in the world.’