The headlines have not been kind to the British banking sector lately. The Financial Times (FT) reported Monday that the professional services firm EY sees London losing 83,000 jobs over the next seven years, if euro-denominated clearing shifts to Europe (the London Stock Exchange put the figure at 100,000 in September). That bleak forecast came shortly after the Sunday Times reported that Citigroup Inc. (C) plans to move 900 jobs, around 10% of its UK-based workforce, to Dublin.

Citi is not the only bank working on an exit plan.

Few think that London's banking sector, which exploded following the 1986 Big Bang of financial deregulation under Prime Minister Margaret Thatcher, will disappear as a result of Brexit. There is little certainty, however, regarding the fate of British banking's passporting rights, which currently allow its firms to operate anywhere in the European Economic Area without securing approval from individual countries' regulators. If the government keeps to its aggressive timetable on leaving the European Union (EU) – triggering Article 50 of the Lisbon Treaty by the end of March, and leaving the trading bloc within the following two years – banks will not have time to plan for changes to cross-border agreements. As a result, many are already shifting functions out of Britain.

Citigroup's choice of Dublin highlights that city's attraction as both English-speaking and within the EU, but the bank had a clear reason to favor Ireland that others don't: it already has a subsidiary in the country, which is separately capitalized. Citigroup announced in June, prior to the referendum, that it would shift its relatively small European retail operations from London to Dublin.

Fewer than a quarter of City of London voters chose Leave. See full map.

Frankfurt, where the European Central Bank (ECB) is headquartered, is another frequently floated option. Goldman Sachs Group Inc. (GS) is considering moving some assets and functions to the former West German capital in order to retain access to the European market post-Brexit, according to unnamed sources quoted by Reuters Wednesday, but no final decision has been taken. Germany appears keen to peel banking industry jobs away from Britain; the FT reported in October that the country is mulling changes to its labor laws to make it a more attractive alternative to London.

Paris is a potential option as well. Shortly after the referendum in late June, the BBC reported that HSBC Holdings PLC (HSBC) would move up to 1,000 euro-clearing jobs from London to Paris. The bank did not comment on the report. (See also, The European Banking Crisis Explained.)

Not everyone is convinced that Brexit spells doom for London's bankers. The City's new Lord Mayor Andrew Parmley told Sky News Friday, "there are more people working in London in financial and professional services than actually live in Frankfurt – there's a very different scale of operation." He added, "in my view it would take a minimum of 25 years to build the office space, to build the homes, the schools, the hospitals and everything else" that would be necessary in Frankfurt, "so initially, I've got no concerns about this at all."

Few bank bosses appear to agree. According to Reuters, Morgan Stanley's (MS) CEO Rob Rooney told a conference in London in October, "It really isn't terribly complicated. If we are outside the EU and we don't have what would be a stable and long term commitment to access to the single market then a lot of the things we do today in London, we'd have to do inside the EU 27." (See also, Brexit Redux: How Pollsters Got the U.S. Election Wrong.)

JPMorgan Chase & Co. (JPM) CEO Jamie Dimon, speaking to Italy's Il Sole 24 Ore in July, allowed for the possibility of a passporting agreement with the EU, in which case, "we likely would not have to make any change at all." But he cautioned, "I think the European Union will not accept that." In "the worst case scenario," he added, the bank would "have to relocate a few thousand people to other offices in the Eurozone, though the majority would stay in the UK."

The final possible destination for London's lost financial services jobs is New York. Speaking to Bloomberg in September, London Stock Exchange's CEO Xavier Rolet addressed the possibility that Brexit could lead to a mass exodus of financial services firms from the country:

"Is it possible that the whole thing could move? Of course it is. The London Stock Exchange Group via the London Clearing House operates a very successful clearing business and is currently licensed to operate, for example, in what I believe could be the only frankly logical alternative to London if that came to pass, and that is the New York market."

The following month, Lloyd's Banking Group PLC (LYG) chairman John Nelson told the outlet, "There is no way in the EU there is a center with the infrastructure or regulatory infrastructure to take the role London has." He added, "there is only one city in the world that can, and that is New York."