Met Commissioner Sir John Stevens will join the convoy in June

Lady Cynthia Stevens, wife of the Metropolitan Police commissioner, is driving one of the 13 lorries which left from North Weald, Essex.

Among the 100 volunteers are Met and Essex police officers who are taking 300 tons of aid for charity projects.

They will also help build a house for teenagers with learning difficulties.

A home for vulnerable elderly people in the village of Pui will also be opened after a four-year renovation project.

Among the convoy, which also includes members of Rotary International and the Aid for Children charity, is a Romanian-born police community support officer (PCSO).

Now based in west London, Klementina Balint-Egan, 32, will return to her home country to help build the house for teenagers in seven days.

Kensington and Chelsea beat officer Dave O'Grady said: "The house will provide secure and comfortable accommodation for kids who have nowhere else to go that can provide them with the support they desperately need."

He added that help from many west London businesses had made the fourth Convoy 2000 project possible.