LONDON (Reuters) - Royal Bank of Scotland (>> Royal Bank of Scotland Group plc) Chief Executive Ross McEwan said the bank may have to move a small number of staff overseas and called for an end to the uncertainty gripping the main political parties following Britain's vote to leave the European Union.

McEwan said the bank may have to move "tens" of employees from the UK if Britain loses access to so-called passporting rights that allow financial services in one EU country to provide services to clients elsewhere in the single market.

"One of the key things for me is holding on to passporting so that European banks and British banks can operate across without any boundaries," McEwan told radio station LBC. "If we don't get the passporting it is inevitable that some jobs will disappear" from Britain's financial industry, he said.

RBS has become focused on banking in the UK and Ireland since being rescued with a 45.5 billion pound taxpayer bailout at the height of the financial crisis, meaning it would likely move fewer employees overseas than larger global investment banks.

Morgan Stanley (>> Morgan Stanley) and HSBC (>> HSBC Holdings plc), for example, may have to move roughly 1,000 employees currently in Britain to elsewhere in Europe if Britain quit the EU, according to people familiar with their plans.

McEwan, a New Zealander, said he was surprised by the result of the referendum and said the focus should now be on ending what he called the first period of political stability in Britain in decades.

Britain's two main political parties have been riven by inner turmoil in the days after the referendum outcome and resignation of Prime Minister David Cameron. Five candidates are vying to succeed Cameron as Conservative Party leader and prime minister, with interior minister Theresa May the frontrunner.

Meanwhile, the vast majority of the main opposition Labour Party's lawmakers have openly denounced leader Jeremy Corbyn as unfit for the job.

"Talking to my friends down in Australia and New Zealand, they are just stunned at what has happened here and seeing so much uncertainty boil up so quickly in the UK," he said.

McEwan said the result may delay return the return of RBS to private hands by a couple of years because of a fall in the bank's share price and a predicted slowdown in the economy.

"People stop making investments when there is uncertainty," he said. "This is a political issue, this is not a banking crisis."

(Reporting By Andrew MacAskill, editing by David Evans)