The new development came just four days after Hawlader was removed from the party's secretary general post.
“Ruhul Amin Hawlader has been appointed as the Jatiya Party Chairman's special assistant. He'll discharge all the organizational responsibilities of the party chairman in his absence,” said a party press release.
It also said Hawlader will hold the No 2 position in the party next to the chairman.
Ershad took the decision as per section 20/1/A of the Jatiya Party constitution with immediate effect, the press release added.
Earlier on December 3, Ershad made party presidium member Moshiur Rahman Ranga its secretary general removing Ruhul Amin Hawlader from the post.
Ranga, also the State Minister for Local Government, Rural Development & Cooperatives, is discharging the duty of party secretary-general alongside party's presidium member as his additional charge.