The UK's biggest banks have drawn up a secret list of demands for politicians if the country chooses to leave the EU, calling for a bonfire of red tape, open borders and a publicity drive to bolster the UK's status as a financial centre outside the EU.Business group TheCityUK - which opposes a Brexit - has warned that leaving would damage financial services, drive jobs to the European continent and harm the economy.But confidential documents show the group has a plan to mitigate that damage and even believes it would be possible to publicise a "relatively better long-term economic outlook for the UK", which would "promote financial stability" outside the EU.The plan sets out "key policy asks", which the group - made up of banks, including Citigroup and Lloyds, law firms and insurers - will put to the government if voters choose Brexit. Initial steps involve exiting smoothly with a "transitional period" to ensure "nothing changes overnight".Finance firms want to ensure the UK retains as much of its access to the single market as possible and adopts a mechanism similar to the passporting regime, which allows firms in the UK to operate across the EU.An independent UK needs to work hard to "maintain London's international competitiveness" as "opening up markets outside of the EU is crucial", the documents say.That means promoting a level playing field in global financial regulation, throwing the UK fully into a leading role in the G20, Financial Stability Board, Basel Committee, World Bank and International Monetary Fund.It also means slashing red tape. The proposals suggest "rethinking the UK's regulatory approach . to support jobs, growth and competitiveness".Banks and finance firms are keen to ensure the finance sector is not cut off from the international jobs market.By contrast, if voters decide to remain, TheCityUK wants UK policymakers to engage more vigorously with Brussels. It also proposes "better engagement of the UK parliament, with full scrutiny of EU proposals".In addition, it would like to see "more UK officials in EU institutions; seen as an important part in a senior civil servant's career". ..