Banks are calling on U.K. Prime Minister Theresa May to guarantee that the nation's exit from the EU will start with a transitional deal that would maintain their access to the bloc's single market for several years, the Financial Times reported Dec. 9, citing a draft of a British Bankers' Association report.

The BBA reportedly wants the deal for a "bridging" period to be in place until a permanent agreement for the new trading relationship between the EU and the U.K. has been finalized. In the event of significant changes for the banking industry post-Brexit, the association would then like to see an additional "adaptation" period for lenders, the FT noted.

May recently hinted that she would seek a transitional deal, saying she understood that businesses did not want to find themselves "on a cliff edge."