There had also been concerns in the party about suggestions she would use this Budget to raise income tax rates, a move that would have broken the party’s election manifesto promise.
The government now appears to have stepped back from that proposal.
Instead, it could consider extending the freeze on the levels at which people start to pay income tax, meaning more people are drawn into paying more tax on their wages and pensions over time.
The chancellor could also look at a range of smaller measures to raise money including new taxes on high-value homes in England, electric vehicles and gaming companies.
She needs to find more money in order to meet her own rules aimed at reducing debt and borrowing.
Reeves has also suggested she will scrap the two-child benefit cap, which limits the benefits parents can claim for their third child or subsequent children born after 6 April 2017.
Conservative shadow chancellor Mel Stride said he worried the Budget would see “tax on hard- pressed hard-working people being transferred into the benefits system”.