National Australia Bank (NAB), owner of Clydesdale Bank, plans to demerge the Glasgow-based institution, handing 80 per cent of the bank to shareholders and floating the rest in Australia later this year.

The shares will be traded on an Australian market and the London Stock Exchange.

However, Victor German at CBA has said the UK’s new bank profits tax could reduce the value of the bank by as much as $425 million AUD - around £200 million.

His report says the tax would reduce Clydesdale’s full-year 2016 pro forma earnings by around 10 per cent and its full-year 2020 forecast earnings by around 8 per cent.

Mr German, who said the tax changes “appear to be detrimental to NAB’s aspirations in listing its UK assets”, claimed the bank’s lower value could cause NAB to sell a larger stake in order to meet its capital-raising targets.

He said: “Moreover, all other things being equal, we believe NAB may need to sell a larger percentage of shares to meet its capital targets (that is, be at the upper end of the 20‑30 per cent range).”

A spokesperson for NAB told the Melbourne Herald Sun: “A higher corporate tax rate for UK banks is a disappointing outcome, however it will be immaterial to NAB’s earnings.”