The British duo are front-runners for selection by the South African team as the list will be whittled down to nine riders for the start of the 2016 Tour in Normandy on Saturday, July 2.
Cavendish would go into the Tour as one of the race's most successful riders, and will be seeking to add to his career tally of 26 victories. The 31-year-old Manxman is currently third in the all-time list of Tour stage winners behind Eddy Merckx (34) and Bernard Hinault (28).
Cummings, 35, has enjoyed a successful 2016 to date, using his talent for late attacking to win stages of Tirreno-Adriatico, the Tour of the Basque Country and the Critérium du Dauphiné. Last year, Cummings won stage 14 of the Tour.
Eritrean star Daniel Teklehaimanot is another rider named on the long list that is almost assured a place. He held the King of the Mountains lead for a spell during last year's Tour, and won the mountains classification at the 2016 Critérium du Dauphiné for a second successive year.
Norwegian Edvald Boasson Hagen is enjoying a resurgence in form, having won a stage and the points classification at the Dauphiné. He won two stages in the 2011 Tour while with Team Sky.
The final roster for Dimension Data's line-up with consist of key support for Cavendish in the sprints, as well as a selection of riders seeking opportunites on hilly and mountain stages – such as Cummings, Boasson Hagen and Teklehaimanot.
Dimension Data long list for 2016 Tour de France
Natnael Berhane (Eri)
Edvald Boasson Hagen (Nor)
Mark Cavendish (GBr)
Steve Cummings (GBr)
Bernhard Eisel (Aut)
Tyler Farrar (USA)
Jacques Janse van Rensburg (RSA)
Reinardt Janse van Rensburg (RSA)
Serge Pauwels (Bel)
Youcef Reguigui (Alg)
Mark Renshaw (Aus)
Daniel Teklehaimanot (Eri)
Jaco Venter (RSA)
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