Donald Trump's plan for reforming federal taxes has apparently been scrubbed from his campaign website just hours before the Republican presidential candidate is scheduled to deliver a speech on economic policy.

Trump's position page on taxes, which previously spelled out his ambitious proposal for lowering tax rates and moving millions of households off the federal tax rolls, on Monday displayed a "404 — page not found" error message.

Trump was expected to discuss cutting federal regulations and instituting a new tax deduction for child care in his speech Monday in Detroit.

Meanwhile, tax analysts have been waiting for the campaign to introduce a revamped tax reform proposal that has been in the works for months. Trump's campaign has been working with outside advisers, including prominent supply-siders Stephen Moore of the Heritage Foundation and CNBC host Larry Kudlow, to alter the plan to lower its toll on federal coffers. The original version of the plan, which Trump rolled out during the primaries, would have lost the Treasury about $10 trillion over 10 years, according to multiple outside analyses.

The campaign has not given a timeline for the introduction of the updated tax reform plan, although advisers have hinted that the changes would reduce the overall cost of the reform and bring it closer into line with the tax overhaul proposal submitted by House Republicans in June.