Sir John Vickers and his four commissioners have made it clear they do not believe the threats made by big banks that they might quit the UK rather than deal with proposed measures to avoid another taxpayer bailout of the financial system.

In the runup to the much-anticipated interim report, banks such as Barclays, HSBC and Standard Chartered all pointed to the potential extra cost of doing business in the UK.

Barclays has been linked repeatedly with a move to the US, while Standard Chartered and HSBC could switch to the far east. There has been speculation that Paris is keen to attract HSBC.

But Vickers said banks considering "hopping jurisdictions" would have to consider what their customers would think about a decision to move abroad. "Any board contemplating moving would need to pay very careful attention," Vickers said.

"One needs to cast a very sceptical eye on remarks of that kind. There will be a whole host of practical obstacles, legal obstacles and reputational obstacles."

Commissioner Clare Spottiswoode, a former gas regulator, said savers might be concerned if a bank leaving the UK was not covered by the government scheme that protects savings.

The 208-page report – which calls for the retail banking operations of major banks to be ringfenced with more capital than the rest of the bank – contains an analysis of the proposals' implications for London as a financial centre.

It concludes that the ideas will have a "broadly neutral effect on financial services" but argues that structural reform of the banking sector could "enhance the attractiveness of London as a place to do business for some financial institutions".

The commission also took a detailed look at the role the UK banks play in cementing London's position as a financial centre and concluded that "the British banks and the City have important linkages, but the historical record does not suggest the participation of the former is obviously key for the success of the latter".

The report weighs up arguments that its proposals might result in banks moving overseas but concludes that while they might "affect the attractiveness of the UK for some parts of those firms", the loss to the exchequer would not be substantial, because only £6bn of the £53.4bn paid by financial services to the exchequer in 2009-10 came from corporation tax.

"Clearly the reforms would require some potentially costly adjustments and expose to increased regulation those banks directly affected, which might affect the attractiveness of the UK for some parts of those firms. However, the commission has received little evidence to suggest that these or other factors would change materially for unaffected firms, nor that the other factors that make the UK attractive would worsen materially for affected banks," the report says.

"Rather it may be the case that the effect on some factors would be positive if the reforms succeeded in improving domestic financial stability, allow for a more predictable fiscal and regulatory environment," it concluded.