Parameshwara in his September 7 letter stated, "In spite of the request you (Shivashankarappa) were absent in the meeting without any prior intimation.
"As it is an election year, your absence in the office bearers meeting held on August 27 is of very serious nature," he said.
Parameshwara said the participation of Shivashankarappa was very important and would help in building the party organisation and sought his cooperation.
In a veiled warning, Parameshwara wrote, "In case, if you are unable to give enough time to participate in the party work, please inform me so that alternative arrangements can be done."
Shivashankarappa, a prominent educationist who runs several educational institutions, including medical and engineering colleges in Davanagere, has been leading a campaign seeking the post of KPCC president to the Lingayat community.
Recently a delegation of Lingayats, to which he belongs, visited Delhi to press for the demand.
Shivashankarappa has said the demand for the president's post to a Lingayat leader ahead of next year's assembly polls remained and it was for the Congress high command to decide.
Meanwhile, Shivashankarappa when contacted by PTI refused to comment on the letter and said, "I will meet Parameshwara tomorrow and talk to him."
