LONDON — A leaked document says the British government is planning for a disruptive "no deal" Brexit under the codename Operation Yellowhammer.

A news photographer snapped a Treasury briefing paper headed "Operation Yellowhammer" being carried into a meeting.

It says the Civil Contingencies Secretariat, set up to respond to floods, epidemics and other disasters, has held a workshop to review government plans for leaving the European Union without a deal on divorce terms and future trade.

The document says it's vital to make a cross-government plan "to help maintain confidence in the event of contingency plans being triggered."

With Britain due to leave the EU on March 29, the U.K. has stepped up planning for a "no-deal" Brexit, which could disrupt trade, transport and other sectors of the economy.