The Mongrel Mob has guaranteed that Electoral Commission staff will be safe when they visit the gang's headquarters on the East Coast.

"I can guarantee them that wherever they're going to go, they're going to be safe, which I know they were concerned of," Hastings Mongrel Mob president Rex Timu told Newshub.

The gang had asked electoral staff to visit to enrol its members, but the Electoral Commission initially turned down the request.

Chief electoral officer Alicia Wright says the commission is always "trading off duty of care" and ensuring staff are safe, while still encouraging everybody to vote.

The refusal prompted Timu to speak up and guarantee their safety.

Wright says nearly one million people failed to vote in the last election and it is important to make sure as many as possible vote in this one, "regardless of criminal affiliations".

Advanced voting for the general election has begun.