Kinnock has hailed Ed Miliband's "magnificent" first speech as Labour leader, telling activists: "It's just like the good old days."
The former Labour leader said Mr Miliband would bring back the golden era, when Labour was basically powerless, impoverished and run by the unions.
"Labour will finally get back to doing what we do best - carping from the sidelines about how this country is going to the dogs, without actually having to do anything about it."
Lord Kinnock, who was a prominent supporter of Ed Miliband during the leadership contest, said he had "ignited with truth, with candour, with absolute honesty what we stand for, and what we stand for is ignominious defeat, irrelevance and double-dealing" in his speech to delegates on Tuesday.
"I see so much of myself in Ed", he admitted.