A bench of Acting Chief Justice Gita Mittal and Justice C Hari Shankar said the appeal filed by Mr Kejriwal and AAP leader Ashutosh against the July 26 decision of a single judge was "misconceived and is devoid of merit".
"Hence the appeal is dismissed. They (AAP leaders) should not have filed this," the bench said. The high Court observed that expedition of trial is the "need of the hour" and recommended the same in all cases.
It also said that the application against the single judge's directions was misconceived and "with the intention" to protract the hearing.
The court also noted that the Aam Aadmi Party leaders had admitted that disparaging remarks had been made by Arvind Kejriwal's former lawyer Ram Jethmalani during cross examination of Mr Jaitley.
The court had on August 25 rapped the Delhi Chief Minister for questioning a single judge's decision to expedite the hearing of a defamation suit filed by Mr Jaitley. It had said that the court had to answer the Supreme Court on delay in trials.
The court had on July 26 directed the joint registrar to expedite the recording of evidence in the civil defamation suit while disposing of an application filed by Mr Jaitley.
Besides Mr Kejriwal, the five other accused in the defamation case are AAP leaders Raghav Chadha, Kumar Vishwas, Ashutosh, Sanjay Singh and Deepak Bajpai.
They had accused the BJP leader of corruption as the president of the Delhi and District Cricket Association (DDCA), a post he had held from 2000 to 2013.
Mr Jaitley, who denied all the allegations levelled by the AAP leaders in December 2015, had claimed that they made "false and defamatory" statements in the case involving the DDCA, thereby harming his reputation.