Rachel Reeves admits Labour has “disappointed” people while in government.
The politician said she understood that being Chancellor meant making unpopular decisions.
She told an audience at the Edinburgh Fringe Festival that Labour had got the balance right between tax, spending and borrowing.
But she said that balancing the books meant making tough decisions, even if the are unpopular.
Appearing on the Iain Dale All Talk fringe show, she said: “The reason people voted Labour at the last election is they want to change and they were unhappy with the way that the country was being governed.
“They know that we inherited a mess. They know it’s not easy to put it right, but people are impatient for change.
“I’m impatient for change as well, but I’ve also got the job of making sure the sums always add up – and it doesn’t always make you popular because you can’t do anything you might want to do. You certainly can’t do everything straight away, all at once.”
Ms Reeves pointed to Labour’s £200 million investment in carbon capture in the north east of Scotland, which she said was welcomed by the industry.
At the same time, Labour’s windfall tax, she said, was not liked by the sector.
“I can understand that that’s extra tax that the oil and gas sector are paying, but you can’t really have one without the other,” she said.
Defending Labour’s record, she said her party had the “balance about right”.
“But of course you’re going to disappoint people,” she added. “No-one wants to pay more taxes.
“Everyone wants more money than public spending – and borrowing is not a free option, because you’ve got to pay for it.
“I think people know those sort of constraints, but no-one really likes them and I’m the one, I guess, that has to sort the sums up.”
Ms Reeves said Labour had to deliver on its general election campaign of change, adding that her party did not “deserve” to win the next election if it does not deliver the change it promised.
