When Rachel Reeves delivers her inaugural Mansion House speech on Thursday evening she will be met, as is customary with a round of polite applause from the great and good of the City of London.

Behind the scenes, however, many of the senior figures in the business world who backed Labour before the election are now having significant misgivings.

Reeves’s first budget was built on the backs of business, with a £25 billion annual increase in employers’ national insurance contributions.

The chancellor was unapologetic, arguing that companies could trim their cloth accordingly and absorb the costs. Instead, some of Britain’s biggest companies are warning of price increases and job cuts as they attempt to protect shrinking profits.

It is a far cry from the