Dhaka, Dec. 5 -- Gravely ill BNP Chairperson Khaleda Zia is being flown to London for advanced treatment, back to the city where her son, de facto party chief Tarique Rahman, has lived in exile for 17 years -- rekindling fresh doubt over his long-promised return.

The 79-year-old chairperson of the Bangladesh Nationalist Party (BNP) has spent the past 11 days in an "extremely critical" condition at the private Evercare Hospital in Dhaka. Doctors now say she is just stable enough to travel.

Her planned departure comes with Bangladesh already in election mode, barely a week before the schedule is due to be announced for February's 13th parliamentary polls.

The BNP had earmarked three constituencies for Khaleda in their initial candidate l...