Burnham also said that there was “definitely a case” for the return of a 50 per cent top rate of tax for the wealthiest, which was brought in by Labour in 2010 but reduced to 45 per cent in 2013 by the coalition government.

Sarah Coles from the investment platform AJ Bell said: “Promising to stick to fiscal rules means that if costs go up and you need more tax revenue, you will have put yourself in a bit of a bind and will have to tinker around the edges.”

Ms Coles said: “Businesses have been feeling the squeeze from recent policy changes, so the prospect of some of that easing will be really positive for those who are struggling.”

She said that overall Burnham was considered to be “soft left”. “You would think this would be a bonus for people who are on lower incomes who could look forward to someone looking out for their interests,” she said.