LONDON (Bloomberg) — Chancellor of the Exchequer Alistair Darling will call on British banks to plan for their own demise by drawing up plans to unwind their businesses in case they fail, a person familiar with the plan said.

The demand is part of a Treasury proposal for legislation tightening regulation of financial services. Darling will make a statement to Parliament about his plan tomorrow at 12.30 p.m. London time.

The rules are aimed at preventing a repeat of turmoil in financial markets that forced Britain to rescue Royal Bank of Scotland Group Plc and Lloyds Banking Group Plc last year. Prime Minister Gordon Brown's government is coordinating the overhaul with President Barack Obama's administration in the US.

Darling will redraw British rules to force bondholders to share losses with equity owners during bankruptcy and take steps to disclose trades of complex derivatives, the person said.