Ed Miliband has made his first visit to Bradford since Labour's shock by-election defeat in the city two weeks ago.
The party leader scrapped a planned victory visit last month after Respect candidate George Galloway swept to a dramatic win in the formerly safe Labour seat of Bradford West with a majority of more than 10,000.
Mr Miliband pledged to learn from the humiliating loss, which was triggered when Labour MP Marsha Singh was forced to stand down because of ill-health.
Speaking to an audience of about 100 people at a community centre in the West Yorkshire city, the Labour leader said: "I am determined to learn the lessons of why we lost here in Bradford.
"I may not agree with everything that is said but I guarantee you I will listen. There are factors local to Bradford but there are factors which are relevant nationally and internationally too."
He added: "There are huge issues of injustice in this country and I passionately believe in the Labour Party being able to change people's lives for the better.
"We can only do that if we are rooted in the communities we serve. We are not going to put everything right today. But we can at least make a start."
Speaking earlier on a visit to Derby, Mr Miliband said only four out of 10 voters supported the three mainstream political parties in the Bradford West poll.
He said: "The fourth party who says 'a plague on all your houses' is an issue we've got to confront. Now, how do we confront it? By showing what we all believe, which is that we can make a difference to people's lives."
Mr Miliband went on to insist that his party was embarking on "real, deep, genuine change" to reconnect with disenchanted voters.