By Charlie Conchie Treasury officials have been hitting the phones to City firms over the past two weeks as Rachel Reeves prepares to deliver the government’s annual Mansion House speech to the financial services sector. The backdrop is a fractious one for the Chancellor. While the Labour party built cordial ties with the Square Mile in the run up to the election, the mood has since soured on the back ofthe £40bn tax bill primarily targeted at business and the wealthy. The Chancellor will now have a chance to lay out a more positive vision for the City’s role in the economy – but there are sev…