According to the report, ex-UK Prime Minister Boris Johnson had a "firm 67" nominations as of Friday, while House of Commons Tory Leader Penny Mordaunt secured only 19 endorsements.
But Sunak was leading the race of three with 100 backers including Johnson's former deputy prime minister Dominic Raab as well as Johnson's former health secretary Sajid Javid, who are both supporting the 42-year-old who resigned as Johnson's Chancellor of Exchequer in July.
Sunak's resignation, in combination with Javid's resignation, eventually led to Johnson having to step down as prime minister following the Chris Pincher scandal.
Johnson has not relinquished any efforts to return to Downing Street, however, after he first stepped down as prime minister in July following a tirade of scandals and a fallout in his government. Mordaunt, who is not as well known among the public, polls well with Conservative Party members.
Sunak, who is leading in a race to become the third prime minister the UK has had in the last eight weeks, is a former finance minister who called ex-UK Prime Minister Truss' tax plan "fantasy island" economics.
On Friday, Robbie Moore, the member of parliament for Keighley and Ilkley, told the broadcaster that it was "very realistic" for him to think that Mordaunt would be able to secure the support of 100 party members to participate in the next round of the run for the post on Monday.
A Conservative leadership contender needs at least 100 party nominations to get on the ballot paper, Graham Brady, the head of the Conservative Backbench 1922 Committee, said.
Outgoing UK Prime Minister Liz Truss stepped down after just six weeks in office, becoming the shortest-serving prime minister in UK history. The choice falls back to the front-runners in the summer leadership contest that followed Johnson's abrupt resignation. The result of the vote is due on October 27.