With pollsters forecasting a resounding defeat for the Conservative party in the July 4 elections, speculation is rife about a Tory leadership contest after the election.
If Labour wins by a landslide, Sunak is expected to give up his leadership position in the Conservative party.
Former home secretary Dame Priti Patel is being seen as one of the frontrunners, The Telegraph reports.
Her supporters see her as a unifying force that will help end party infighting and feel she will be a credible leader of opposition.
Patel is currently focussing on retaining her Witham constituency seat in Essex and may decide after the elections.
The other names doing rounds include Penny Mordaunt, the Commons leader, and Kemi Badenoch, the Business Secretary, provided they maintain their seats.
A recent Ipsos poll has forecast that Mordaunt would face a close contest at Portsmouth North seat.
Other contenders could include Robert Jenrick, the former immigration minister and Suella Braverman, the former home secretary.
Patel was the home secretary under Boris Johnson and continues to be his loyalist. She also Sunak for his Rwanda legislation.
Though Patel is on the right of the party, she is said to be in touch with the centrist One Nation group. She reportedly has the backing of some centrist figures such as former chancellor George Osborne and former justice secretary David Gaukelie.
Most leadership aspirants are reportedly jockeying for support from other Conservative contestants who are expected to win this election.
