Rachel Reeves MP said her party had spent too much time focusing on non-mainstream issues that were of no interest to voters and had cost Labour dearly at the ballot box.
She said they would get "back on track" by showing people Labour was a "pro-business" party that could be trusted with taxpayers' money.
Mrs Reeves, MP for Leeds West, was in the Black Country on Thursday to visit Richardsons in Oldbury and Westfield Sportscars in Kingswinford.
She said: "Labour looking inwards and focusing on issues that are not mainstream for people in Dudley, Walsall, West Bromwich and Wolverhampton has resulted in the loss of some fantastic members of Parliament for this region.
"I'm determined under the leadership of Keir, that we get the Labour Party back on track."
She conceded the party still had a "lot of rebuilding to do" after taking a pasting in the 2019 general election and recent council elections, which saw the Conservatives take a firm grip across vast swathes of the region.
"We are making progress but we still have a lot more work to do to win back that trust that we've lost over a number of years," Mrs Reeves said.
"I've been showing voters that they can trust Labour with their money, and that we would treat every penny of taxpayers money with respect.
"The Tories are wasting money and it is not going into our frontline public services.
"We are saying very clearly that while the Conservatives are becoming increasingly a populist party, Labour are a pro-business party.
"We want to get back in the game and show that we are a party of job creation for all parts of the country."
During her visit to the Westfield site at Gibbons Industrial Park, Mrs Reeves met with staff and bosses and discussed vehicle production. She also took to the roads to test drive a retro electric Porsche Speedster.
The MP said: "The exciting thing at Westfield is that while it is a reminder of the region's industrial heritage, it is also a big part of the future.
"A Labour government would want to work hand in glove with businesses like Westfield to ensure that we are investing and supporting the jobs and industries of the future."
She also urged the Government to "deliver on their promise" to have a gigafactory to build batteries for electric vehicles in Coventry.
"I think that could really help the car manufacturing sector in the West Midlands," she said.#]
"This region was home to the industrial revolution and it can be home to the zero carbon revolution, but there's a global race on to secure these jobs and investment.
"At the moment this government is lagging behind other countries. There is a gaping gap between the rhetoric and the reality."