The work, which will begin early in the new year, will involve repairs to the clock’s hands, mechanism and pendulum.
The Big Ben bell after which the Palace of Westminster’s ElizabethTower is more commonly known will fall silent to allow the work to take place.
It will be the first time Big Ben has been silent since 2007, the BBC reported.
After the final tours have taken place on Friday, the erection of scaffolding will begin early in 2017 and is expected to take four to six months to complete.
Parliamentary officials said the mechanism of the clock was in a ‘chronic state’, with fears that it may fail if work is not carried out urgently. There are also concerns that the fabric of the tower itself is reaching an ‘acute’ condition.
A lift will be installed and the 157-year-old tower will be upgraded to bring it into line with modern health and safety standards. The lift will provide greater access for disabled people who are unable to climb the tower’s 334 steps.
It is more than 30 years since the last significant conservation work took place on Big Ben, between 1983 and 1985.
Clock faces will be covered, although at least one will remain visible at any time, and bells will toll for important events such as New Year’s Eve and Remembrance Day.