The Conservative backbench 1922 Committee has decided not to change rules which require a 12-month delay between confidence votes in the party leader.
As a result, Theresa May cannot be challenged until December.
However, officials have asked Theresa May for a clearer timetable for her departure, according to Sky News.
If the time limit had been shortened to six months, May could have faced contest as early as June.
The chairman of the 1922 Committee, Sir Graham Brady, said:
“We further determined that we should remind colleagues that it is always available to them to write to me as chairman of the 1922 Committee raising concerns or setting out their thoughts, including concerns about the leadership of the party, and that the strength of opinion would be communicated by me to the leader of the party should they decide to do so.
“Thirdly, we determined that following the Prime Minister’s decision a few weeks ago to set out a clear schedule for departure as leader of the party in the event of the Withdrawal Agreement being passed, we would seek similar clarity from her in other circumstances.”
He added: “I think the 1922 executive is asking on behalf of the Conservative Party in Parliament that we should have a clear roadmap forward.”