Nawaz Sharif and Maryam Nawaz arrived in London on Thursday to see Kulsoom Nawaz, who is currently undergoing cancer treatment.

Sharif and Maryam boarded a foreign airline flight at the Allama Iqbal International Airport and arrived in London via Doha.

After boarding the plane Maryam tweeted: "Leaving for London. (We) will be back next week. I can’t wait to meet and hug Ami. I request you all for special dua for her health."

There are reports that the condition of Kulsoom — who is in the advanced stages of lymphoma (throat) cancer — has deteriorated and she has been shifted to hospital.

Upon reaching London, Maryam tweeted that her mother had a heart attack earlier in the day. "Ami had a sudden cardiac arrest this morning when we were on the flight and is in ICU and on the ventilator since. Earnest request for duas."

Hassan and Hussain Nawaz, and other family members are also in London, a top PML-N source told DawnNewsTV. The family is constantly in touch with doctors, the source said.

The Sharif family members’ departure could only be possible after the caretaker government neither rejected nor accepted the National Accountability Bureau’s plea to place their names on the ECL.

NAB in its request to the interior ministry had expressed the fear that they (Nawaz and Maryam) might not return to the country to face corruption references against them, saying: "There is apprehension that they may leave the country to avoid legal outcome of the judgement which is expected to be announced shortly."