London’s attempt to maintain its financial muscle while boycotting Europe’s move toward a banking union risks isolating the city from its major trading partners and undermining its status as the world’s top money centre.

The European Central Bank (ECB) will become the main regulator for the biggest banks in the euro region as early as January, the first step toward a banking union, EU leaders agreed to last month. Britain has said it would not take part and was negotiating to retain London’s influence within the single financial market.

The danger of a banking union that did not include the UK was that Britain’s voice in setting the rule-making agenda would be weakened as the ECB gained new powers, bankers said. Trading in euro, now centred in London, could shift to Frankfurt or Paris in Europe’s core and be regulated by the ECB, said Thomas Huertas, a former UK representative on the European Banking Authority, which drafts financial rules for the 27-nation EU.

“If there is a European banking union and a notable missing member of that is the UK, then that will likely hurt London as a major financial market,” said Jay Ralph, the management board member responsible for asset management at insurer Allianz. “A strong pan-European banking union ex the UK will have negative implications for Europe and the UK.”

London, the world’s biggest centre for foreign-exchange trading, cross-border bank lending and interest-rate derivatives, has 251 foreign banks and more international firms than any other financial centre including New York or Frankfurt, according to bank lobby group The City UK.

The City, as London’s financial district is known, is home to three-quarters of the EU’s foreign-exchange trading, including 42 percent of euro trades. Banks located there conduct about 62 percent of trading in euro-denominated, over-the- counter, interest-rate derivatives, the group said.

A European banking union giving the ECB new supervisory powers would create an “inner core” of euro-region nations that sidelined the rest of Europe, including the UK, said Huertas, who now works for Ernst & Young in London. Two sets of regulations for so-called inner and outer Europe would mean UK banks would not have easy access to European markets.

“Most dollar capital-market business and most dollar business for the domestic US market occurs inside the US,” Huertas said. “It’s entirely possible that euro business moves from London to the Continent.”

The concern for UK banks was that “you end up with a policy-weighting toward the euro zone banks because they’re in aggregate bigger – that could damage the single market”, Douglas Flint, the chairman of HSBC Holdings, Europe’s largest bank, said. A banking union “has to be done in a way that preserves the integrity of the single market in financial services so that banks within Europe but not within the banking union are not disadvantaged.”

David Walker, the chairman of Barclays, Britain’s second-largest lender by assets, echoed Flint. “Because we are not in the euro area, their shaping the union and equipping the European Banking Authority will be less sensitive to our concerns,” Walker said at a bankers’ conference in London. “We will see some undermining of the single market, some protectionism of the financial-services sector.”

Much of the structure and timing of a banking union remains to be negotiated, and that is adding to uncertainty in London, according to senior executives at US and European banks in the City, who asked not to be identified because they were not authorised to discuss company positions.

In addition to common supervision, a banking union could mean that governments share the costs of winding down failed lenders and guarantee deposits, or leave that to national regulators. In the meantime, a central supervisory authority could allow the region’s bailout fund, the E500 billion (R5.6 trillion) European Stability Mechanism, to directly recapitalise firms, breaking the link between sovereigns and their lenders.

The UK does not want to be part of a banking union because it does not want to be responsible for paying for failed banks in Spain and elsewhere in the euro area, according to top government officials. Britain should stay outside because the plan was designed to address the “vicious circle” between sovereign debt and banks in those countries, Deputy Prime Minister Nick Clegg said in a speech last month.

“The worst outcome would be the creation of an over-powerful banking bloc,” said Clegg, whose coalition government is facing pressure from inside the Conservative Party to hold a referendum on the UK’s relationship with the EU. “The rest of Europe needs to be crystal clear: If they integrate in a way that hurts the City, they potentially hurt Europe as a whole.”

Charles Bean, the deputy governor of the Bank of England, said the bank shared the government’s view that a union would help bring stability to the area and that UK banks should not be a part of it. While the UK belongs to the EU, it opted out of the euro zone established in 1999. “We don’t particularly want to be part of it, so what will be important going forward is that we establish a modus operandi that ensures that decisions that are taken in the European banking union don’t impinge adversely on the way the single market in financial services in Europe operates,” Bean said.

US banks that have built securities-trading operations and European headquarters in Britain as a hub for the rest of the region, share Ralph and Flint’s concerns, according to an executive with knowledge of lobbying by US lenders who asked not to be identified because the effort was private. If a banking union were to leave London isolated from Europe, foreign banks would consider shifting operations to within the euro zone, the executive said.

“A very large proportion of the City is made up of euro area banks, and the question for them is whether being under one supervisory roof will deliver over-time outcomes which affect their activities in the UK,” said David Green, who spent 30 years as a senior supervisor at the Bank of England and then headed international policy at the Financial Services Authority, the UK’s industry regulator.

Spokesmen for British banks, including Barclays, Royal Bank of Scotland (RBS) and Lloyds Banking, declined to comment, as did those for Citigroup, JPMorgan Chase and Deutsche Bank.

“The UK is host to the EU’s main financial centre, and it’s essential that it’s not sidelined in the making of regulations that affect it more than other countries,” said Anthony Browne, the chief executive of the British Banker’s Association, an industry lobby group.

London has withstood past challenges to its dominance. More than 10 years ago bankers in the City were dealing with the bursting of the dot-com bubble and were concerned they would be left behind as the euro zone adopted a single currency. It went on to have its most profitable five years on record.

The City remains the world’s most important money centre because of such advantages as its time zone, language, talent pool and legal infrastructure, according to research firm Z/Yen.

“The effect will not be as much as people say,” said George Mathewson, who retired as chairman of RBS in 2006. “My personal view is it won’t be dramatically bad for the UK. The UK has got some in-built advantages that are difficult to dislodge.”

Ismail Erturk, a senior lecturer in banking at Manchester Business School, felt the same way.

“I doubt Frankfurt can replace London in the near future for euro-denominated businesses. The euro zone banks are interconnected with the US and the big emerging economy banks in wholesale markets… I doubt Frankfurt or anywhere else in the euro zone will be able to accommodate interbank, interest-rate-swap and currency-trading markets.” – Bloomberg