Senior figures associated with the party have argued that the defeated Ed Miliband did not do enough to win over aspirational voters and spent too much time attacking job creators and the wealthy.
Former Prime Minister Tony Blair said Labour must be for "ambition and aspiration as well as compassion and care." Writing in The Observer, Blair argues: "the route to the summit lies through the centre ground."
Blair, the only Labour leader to ever win three elections, urged his party to do more to win over businesses following Miliband's shift to the left. He writes:
We have to appeal to those running businesses as well as those working in them. We need to persuade people that we will run the economy well and efficiently and that must contain a measured defence of our economic record when in government which correctly describes the impact of the global financial crisis of 2008 but also acknowledges where we could have done better.
We have to conduct the big argument on the wealth-creating potential of the macro-economy, not only the targeted campaign on the injustices of it. So we were proud in 1997 to put forward the case for Britain's first minimum wage. But we could never have won an election on it unless set within a broader framework. The same is true with zero-hours contracts.
One potential candidate to replace Labour leader is shadow secretary Chuka Umunna, who put forward a similar case in today's Observer and on The Andrew Marr Show that Labour failed to appeal to middle-class voters by not giving enough credit to wealth creators.
Umunna argued: "You cannot be pro-business by beating up on the terms and conditions of their workers and the trade unions that play an important role representing them. But you cannot be pro good jobs without being pro the businesses that create them.
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"In spite of the fact that our policy offer was pro-business, the rhetoric often suggested otherwise. And sometimes we made it sound like we saw taxing people as a good in itself, rather than a means to an end."
Former Labour business secretary Lord Mandelson, also speaking on The Andrew Marr Show, slammed Ed Miliband's decision to move the party away from New Labour and described his view of the business world as "completely useless".
Shadow health secretary Andy Burnham was made the bookies' favourite to be next Labour leader in the immediate aftermath of Miliband's resignation, yet bookies William Hill has made Umunna the 2/1 favourite in its latest odds.
Other possible candidates include shadow home secretary Yvette Cooper and Dan Jarvis, MP for Barnsley and former paratrooper.