The country's biggest trade union is on track to recruit 5,000 members into Labour this year under moves to “reconnect” with the party.
Unite is also encouraging its activists to join local constituency parties to try to influence Labour's policies.
General secretary Len McCluskey said thousands of trade unionists had "abandoned" Labour in recent years because they felt disengaged from the party.
He told a fringe meeting at Labour's annual conference in Manchester that unions used to be treated like a "nutty relative", kept locked up in the attic and passing cheques under the door.
"That was very hurtful and we are determined to reconnect and get our activists involved again."
Mr McCluskey said the "control freakery" of New Labour had ended, although he complained that debate at the annual conference was still "stifled".
He added: "Getting our political voice back is absolutely essential. We committed to recruiting 5,000 new members into Labour by the end of the year, and we now expect it to be more than that."