House Republicans are poised to pass a major tax bill on Tuesday, which would set the stage for Donald Trump to achieve his first major legislative success in office.

The legislation, finalized in a conference report last week, would lower the top rate on families and individuals to 37% and the top rate on corporations to 21%.

However, in case of any last-minute developments, Vice-President Mike Pence has delayed his plans to travel to the Middle East to be present for the vote. In a statement, his spokeswoman, Alyssa Farah, said: “The vice-president is committed to seeing the tax cut through to the finish line ... [and] looks forward to traveling to Egypt and Israel in February.”

Although Republicans had long hailed tax reform as a way to simplify the United States tax code, it would keep all seven existing tax brackets for individuals and would also add over a trillion dollars to the budget deficit. It also would limit tax deductions for home mortgages and for state and local taxes.

The bill also would have a significant impact on policy outcomes outside the tax code. It would end the individual mandate under Obamacare, which requires Americans to buy health insurance or pay a penalty and open up the Arctic national wildlife reserve in Alaska to oil drilling.

The House passed an earlier version of the tax bill by a margin of 227-205. Every Democrat was opposed, along with 13 Republicans, many of whom represent districts where voters would be hurt by curbing the deduction for state and local taxes.

If this majority holds up on Tuesday, the bill would then go to the Senate, which passed its own tax bill earlier this month by a margin of 51-49. All Democrats and one Republican, Bob Corker of Tennessee, were opposed to the bill. Despite the expected absence of John McCain for cancer treatment, Republicans should have the votes in the upper chamber after Corker announced on Friday that he would support a bill that he labeled “far from perfect”.

With McCain’s absence, it is unlikely that Pence will be needed to break a tie because there will only be an odd number of senators present and voting. However, the former congressman has long been an important part of the White House’s outreach to Capitol Hill and the postponement also allows him to delay his travels until tensions ease over the US’s recognition of Jerusalem as the capital of Israel in December.

Trump’s decision to unilaterally recognise Jerusalem as Israel’s capital has sparked international outcry. The UN security council called for the decision’s withdrawal on Monday, prompting the US to use its veto to block the resolution.

In the aftermath of the US decision, both Mahmoud Abbas, the president of the Palestinian Authority, and Pope Tawardos II, the head of Egypt’s Coptic church, canceled scheduled meetings with Pence during the trip.

Speaking on Monday, Trump pre-emptively heralded the passage of the bill. He told an audience in Washington before laying out his new national security strategy: “We are days away from passing historic tax cuts for American families and businesses.”

The tax bill is not the only major legislation up for consideration this week. Funding for the government is poised to expire on Friday. Many Democrats have insisted that any government funding deal provide protection for “Dreamers”, undocumented immigrants brought to the United States as children.