Miliband is the bookmakers’ second favourite pick, with the former Labour party leader politically closer to Burnham than Streeting.
Paul Johnson, former director of think-tank the Institute for Fiscal Studies, sees this as a positive.
“You really don’t want people in Number 10 and Number 11 having very different views,” he says.
However, opinions differ on whether former Treasury adviser Miliband could rally the markets.
Nick Macpherson, the former permanent secretary at the Treasury, told the Financial Times: “The key to gaining the confidence of the markets is to articulate, implement and deliver a coherent strategy.
“Miliband is one of the few cabinet members with the intellect, experience, and authority to do that.”
Yet, others see Miliband as an inflation risk, believing his drive for net zero as energy secretary as partly responsible for the UK’s high energy prices compared to other countries.
Analysts say that reputation, whether accurate or not, could affect how bond markets react to his time as chancellor.
Meanwhile, the Unite union’s general secretary Sharon Graham says Miliband as chancellor would be a “noose around the neck” of job creation, external because of his opposition to new oil and gas drilling in the North Sea.