Jassar, who died on Saturday at age 77, was mayor in 1990-91 and was a Labour councillor for Hounslow Central ward from 1986 to 2006.
The Hounslow Council has paid tribute to Jassar saying it was saddened to learn the death of former mayor.
He served the Borough as a Hounslow Central ward councillor between 1986 and 2006 and was the Borough's mayor from 1990 until 1991.
The flag is being flown at half-mast in tribute and a minute's silence will be held in his memory at the next full council meeting next month.
More From This Section
Overcoming poverty, he obtained a Masters degree in economics and after a brief spell of teaching in India, he migrated to the UK in 1968 and worked as a civil servant for more than 30 years.
Jassar was conferred the "Freedom of the City of London" honour in 1991 for his tireless charity work in Britain and other countries.
"Freedom of the City of London" is an award given by the local government in a town or city to those who have served in some exceptional capacity.