Shadow Care Minister Liz Kendall said that she is considering a bid for leadership of the Labour Party.
Miss Kendall said a "fundamentally new approach" was needed in the wake of the party's crushing general election defeat, and the subsequent resignation of party leader Ed Miliband.
Other Labour politicians expected to run for the leadership include Yvette Cooper, Andy Burnham and Chuka Umunna.
Kendall, MP for Leicester West, joined Tottenham MP David Lammy in declaring interest in a the job.
In an interview with the Sunday Times, she set out her stall as the representative of the Blairite right of the party, warning that Labour needed to reach out more to middle-class voters.
"We need to show people that we understand their aspirations and ambitions for the future, and if you look right across England, we did not do enough to appeal to Conservative supporters, and we must.
"I think we lost because people didn't trust us on the economy. People didn't think we understood their lives, shared their values and aspirations," she said.
She added that "we don't just need a new face. We need a fundamentally new approach".
Kendall worked for Harriet Harman after the 1997 election, and was a special adviser to Patricia Hewitt from 2004-2007, when Hewitt was Secretary of State for Health.
Former Prime Minister Tony Blair called for Labour to re-occupy the centre ground he staked out in his three successful bids for Downing Street.
"The Labour party has to be for ambition as well as compassion and care," he told The Observer.
"Hard-working families don't just want us celebrating their hard work; they want to know that by hard work and effort they can rise up, achieve. They want to be better off and they need to know we don't just tolerate that, we support it."
Burnham, who is regarded as the torch bearer for the left of the party, remains the bookmakers favourite, at 5/2 odds.