By Charlie Conchie A sweeping hike in capital gains tax (CGT) risks “undermining the chancellor’s growth agenda” and could suck talent and investment away from Britain’s start-ups, top fintech bosses have warned. Industry bodies and tech chiefs mounted a co-ordinated push to topple the suggestion of a blanket rise in CGT yesterday with a call for a carve-out of ‘earned capital gains’, which could shield the equity of start-up founders and staff from a rise in taxes. Start-ups often make up for lower salaries by offering their staff equity in the company. Suggestions that the Treasury could hit…