HSBC chairman Douglas Flint on Tuesday warned that the banking titan could move activities from London to continental Europe ahead of Brexit.

Britain is due to trigger Article 50 by late March, kicking off a two-year process to leave the European Union.

The nation's financial sector has long feared the loss of "passporting" rights -- which allows EU member states to trade across national borders. That provides a crucial gateway for companies to access the rest of the bloc.

"The impact (from the loss of passporting) would start to be seen far before the end of the Article 50 process because there would be a period of time necessary to adjust our" activities, Flint told lawmakers on parliament's Treasury Select Committee.

"We would take pre-emptive actions in order to ensure that we have the capacity in place... to continue to deliver what we deliver today.

"That would require us to move activities (...) to France or indeed Ireland or Holland or any other place in Europe where we have operations. It would be something like 1,000 jobs."

Flint added that the government's lack of Brexit guidance "would lead to people thinking earlier as to where to move jobs".

Following Britain's shock EU exit referendum decision on June 23, Flint had already warned that the bank could potentially move 1,000 British-bases staff to Paris.

Lobby group the British Bankers' Association (BBA) cautioned in October that international lenders with operations in the UK are ready to transfer some of their activities out of the country from early 2017.

Big banks have long harboured fears about the impact of Brexit, including potential loss of access to the single market.

"We are in perhaps a better position than many having a full service bank already in France," added Flint on Tuesday.

"Because we've got operations in France we can take a little bit more wait and see approach than possibly more others.

"Nobody wants to push the button (to leave Britain) because the best outcome for everybody is the preservation of the status quo, insofar as is possible," he said.