Speculation over Dan Jarvis' leadership ambitions continues as he gave a speech in Central London setting out vision for a party that can 'beat the Government'.
The former paratrooper who represents Barnsley Central said he wanted Labour to become the party of work once again, as well as invest more in infrastructure and early years support.
He claims a radical approach is needed to battle against Chancellor George Osborne's 'budget gimmicks' and 'Westminster economics' that he said has seen a decline in exports and real wages falling by £1,600 a year in the last parliament.
Delivering a speech in central London this morning, he said: "The next Labour government must take a more radical economic approach – more radical than we had under Tony Blair, Gordon Brown and Ed Miliband.
"Labour must always be the party of work and jobs, so that nobody is left behind."
"When you hear George Osborne say ‘long term economic plan’, what he really means is ‘short term political gain’.
"That is why people across the country, regard politics as a trade in illusion and self-interest."
Many in the media expected the MP to stand in the Labour leadership following Ed Miliband's resignation, but announced he would not run and later left shadow front bench as foreign office minister when Jeremy Corbyn was elected.
During his 30 minute speech he also backed Leeds West MP and former shadow work and pensions secretary Rachel Reeves, who earlier this week told the Yorkshire Post how the Government must not be afraid to borrow for infrastructure projects that have clear rewards, and the importance of universal childcare.
He said: "The importance of the first 1000 days, by the time a child has reached two, two and a half their life opportunities are largely determined. Although it doesn't sit in the natural culture of political decision making to invest money over the longer term. I absolutely think that should be a priority for a future Labour Government.
"In my Barnsley Central constituency their is a ward called Kingston, and I want the daughter of a cleaner in Kingston to have the same life opportunities as the son of a barrister in Kingston-upon-Thames.
"That is what draws us into the Labour party."
Taking questions from journalists after the speech, he made his first reference to current Labour leader Mr Corbyn by saying he was grateful that he had given the party the chance to discuss ideas.
However he distanced himself from suggestions he is attempting to position himself for a future leader of the party.
He said: "Nobody should be anything other than completely clear that the EU referendum is the most profoundly important decision we have had in our lifetime.
"The public will frankly have very little sympathy for those within the Labour party who are focused on anything other than trying to secure a Labour win in May, and a referendum win in June. I can absolutely tell you that's what 100% of my focus will be on.
"The remarks that I have made to day are in no way seeking to make a critique of anybody in the Labour party. It's a good thing that our leader Jeremy Corbyn wants to have a debate on the future of our party and the future of our country. It's an entirely positive thing. I don't think we did enough of it in the previous Parliament."
He said more focus is need on the party's values and 'defining mission', and that debate can be had in a constructive way.
"We know there are lots of very, very, talented people in the Labour party who are seeking to make a contribution to the party in different ways. I'm now on the back benches and that gives me the freedom and space to make I hope some constructive contributions to an important debate to the future of our party.
"And that is all I'm seeking to do," he said.
Yorkshire MPs, including the former economist and Leeds West MP Rachel Reeves were praised during the speech however he denied the pair were working in tandem on a joint platform on what the economic direction of the Labour party should be.
He said: "Rachel Reeves gave a brilliant speech on Monday to the Social Mobility Foundation and she has a huge amount to contribute. But there's people across the whole movement that have a lot to contribute.
"It's important we don't seek to turn these contributions into an attack or critique of our current leadership.
"People like Rachel, and lots of other people and a number of people including a number in Yorkshire have got a big constructive contribution to make to that process."
The speech was hosted by Demos, and described it as a 'long-planned event' to bring together his thoughts and views after five years in Parliament.
After winning his seat in the Barnsley Central by-election in 2011, he held positions as shadow arts minister and shadow youth justice and victims minister.