The decision was made to avoid intra-party conflict and encourage a participatory election, the party said
"Not only MPs, but the people are not safe now. There's no guarantee of life. All this happens, because law enforcers are being used to serve political purposes," senior leader Mirza Fakhrul Islam Alamgir said on Monday.
Unidentified men shot the Gaibandha lawmaker several times in his house on Saturday. He succumbed to his wounds in a hospital about an hour later.
The ruling Awami League have pointed finger at the Jamaat-e-Islami, a BNP ally, for the killing.
"It's their habit to blame others for their misdeeds. But the truth always comes out," said the BNP secretary general.