Jeremy Corbyn has helped kick-off of Labour's by-election campaign with their candidate Jim McMahon in Oldham.
The Labour leader said rising Labour star Mr McMahon would win voters over for a "decent, better Britain" as his party faces its first big test at the polls since his shock election.
Mr McMahon, 35, has been lauded as a young, pro-business council leader, widely seen as more on the right than the left of the party.
The leader of Oldham Council, he was elected by local Labour Party members last night, beating three more left-wing candidates.
In a fleeting visit to a sometimes chaotic launch at a former pub in the Oldham West and Royton constituency, Mr Corbyn first paid tribute to Michael Meacher, whose death as long-standing local MP triggered the by-election.
Mr Corbyn said Labour's candidate was local and understood local people while the Tory government was imposing "massive cuts" on local authorities, the police and on tax credits.
He said: "The people of Oldham have a chance to decide. Do they want a party in power, the Labour Party in power, that will defend, the interests, the living standards of ordinary people and defend working tax credits and not take £1,300 a year away from three million families across Britain which will in many cases, stop them working, in every case reduce their standard of living?
"It's Labour who are standing up for ordinary people.
"It's Labour who are standing up for people's right and ability to work.
"It's Labour who are standing up for our future and for our children. That quite simply is what the choice is.
"We are going to get Jim McMahon elected for this constituency to show the people of Oldham want a decent, better Britain that cares for all not the few."
Mr McMahon, addressing around 50 supporters at the launch and flanked by his leader said: "I was brought up by a really hard working truck driver. He taught me if you work hard, roll your sleeves up, you can get on in life.
"I don't see that today. I see people working hard for really low wages, in zero hour contracts, insecure employment and that's not the town that I want.
"I want Oldham to be the best it can be. If people are willing to work hard and contribute they should get the reward of that.
"We can only do that if we have a Labour government. I'm happy to stand forward for my town. I'm happy to stand forward for the Labour Party and I'm happy to show Ukip the door."
The party is defending a 14,000 majority in May's General Election, but Ukip saw their vote surge by 17% and have made Mr Corbyn and immigration their main campaign message.
Earlier today Ukip leader Nigel Farage visited the constituency, claiming Labour was a "divided party" between the left and right.