Legislator Abhay Narayan Patel and his son barged into a polling station in Achalnagar in the afternoon and tried to forcibly enter a polling booth.
When the paramilitary trooper objected to their presence, Patel's son threatened him and this led to a brawl.
Officials said that while the Samajwadi Party legislator and his aides were asked to go out of the booth, based on a complaint by the trooper a case was filed against the legislator on several charges, including threatening to kill, intimidation and obstructing in government work.
In some other places too, complaints were received by the Election Commission about Samajwadi Party leaders trying to influence the voting.
A poll panel official told IANS that they will scrutinise the complaints and take action. He added that in the serious complaints, action was taken immediately.