The planned extension of off-payroll rules to the private sector will be included in a review into how the Conservatives could better support the self-employed.
The admission by former chancellor Sajid Javid potentially increases the prospect of the tax measure being delayed.
"In our manifesto, we promise a review of how we can further help the self-employed," Javid told Money Box on BBC Radio 4.
"But one thing in particular I want to look at again are the proposed changes to IR35."
When pressed by host Paul Lewis as to whether the extension of the rules to the private sector may be put off, Javid stopped short of committing to a delay.
"I don't want to pre-empt the review," added Javid. "But it makes sense to include the IR35 changes in that [self-employed] review."
As things stand, from 6 April 2020 medium and large private-sector firms will be responsible for determining whether the rules apply to contractors they engage.
The Liberal Democrats were the first to announce clear plans to review the planned extension should they win the general election on 12 December 2019.
Labour initially said they would scrap the extension, before backtracking and committing to a review.
Talk to us about the IR35 rules.