The Sentencing Council is a non-departmental public body that sets out guidance for courts in England and Wales.
In his speech, Jenrick will accuse the council of watering down sentences by recommending jail terms that fall short of the maximum allowed in law.
“All too frequently the law is not applied equally,” Jenrick will say in his speech.
“No more – every single person in this country must be treated exactly the same, regardless of their background.
“The public are sick of voting for tougher sentences and getting the opposite.”
The party says a Conservative government would introduce new legislation to give the justice secretary the power to issue sentencing guidelines.
Jenrick’s speech comes on the third day of the party’s conference in Manchester, where the Conservatives have faced questions about their flagging poll ratings and their direction of travel under the leadership of Kemi Badenoch.
Speaking to the BBC, Badenoch insisted her approach to changing the party would “pay off eventually” and Jenrick, who was a leadership contender last year, has backed her.
At a conference event on Monday, Jenrick said there was not a leadership vacancy and he did not expect there to be.
“My expectation is that Kemi will lead this party into the next general election,” Jenrick said.